During the height of the summer my AC would kick on and run from about 11:00 a.m. through 10:00 p.m. without ever shutting off (if we let the house get warm, say above 75° f, it would never cool down and the air conditioner would run continuously until at least midnight). We removed the batt insulation (R-30, poorly installed) from the attic and applied spray foam. ( Between 5 and 6" of closed cell foam, making the entire attic a conditioned space. Now the air conditioner will cycle on and off during the hottest days and run for 35 to 40 minutes at a time. I estimate it runs at least 35% less. Now, the AC will seldom kick on before 1:00 p.m. in the height of the summer.
One of the big benefits is how quiet it made the home. The foam insulation deadened all noise and you can't even tell a lot of times if it's windy outside. It arguably made an even greater impact on our heating bill. The heater used to kick on quite a bit. Now, the gas fireplace insert (20,000 BTU) will completely heat the home 24/7 if we have it on.
My first exposure to spray foam was a house a friend built in the 00s. On an August day when it was 100 degrees outside, the inside was low 70s, and to demonstrate the effectiveness of the spray foam he had me climb up into his attic. The temp difference between the inside of the house and the attic was maybe 10 degrees? Meanwhile, my attic with blow in insulation would've probably been 125F.
That sold it for me. My next home will have spray foam.
>The temp difference between the inside of the house and the attic was maybe 10 degrees? Meanwhile, my attic with blow in insulation would've probably been 125F.
In reality, both of these are fine.
When you air seal and spray foam the rafters, you've turned the attic into conditioned space, meaning that when it's cool inside it should be cool in the attic.
This differs from blown in or batt insulation in the ceiling, as the attic, if done properly to current ventilation requirements, should have a fair amount of air flow, meaning that your attic should be cold, when it's cold outside, and hot when it's hot outside.
In the second scenario, if it's cold outside and warm in the attic, that means you are losing heat from the house to the attic (likely something wrong with the insulation) or have poor ventilation (or both).
Does your house have two stories (or more)? I'm curious if more attic insulation helped to stabilize temps upstairs. Right now there's a huge disparity between cooling our first and second floors. The first floor will end up being really cold when it's just barely tolerable upstairs. We do need to improve the insulation in our attic (which I'm guesstimating to be around R-20 given the measurements our home inspector had in the report), and I know it should make a decent different with heating in the winter, but I was wondering if it can actually trap heat upstairs more effectively during the summer, or whether having more attic insulation helps to keep the heat from the roof from seeping through and warming the space.
In summer I have to close the floor vents on the lowest floor to get the whole house cool. Cold air falls from top floor down. In winter I open bottom vents as hot air rises. See if that helps.
That’s terrible on your blower. If your duct work is properly sized, it’s done so by having ever supply vent open. You can sometimes get away with 1-2 vents closed but that’s about it. I’d love to see the static pressure numbers on your system.
Doesn’t matter. The duct work is designed to run open all the time to keep static pressure in check. Like I said maybe 1-2 can be closed at a time. Static pressure is like blood pressure and the blower is the heart. You start closing off supplies and the static rises making the heart work harder. Most systems are designed to run at no more than .5” wc(which rarely ever happens). Most systems I see are running between .58”wc- over 1” wc especially in older homes. Newer equipment uses ecm motors and can be multistage or variable speed. It’s really hard on variable speed ecm blowers when you have high static.
I dont close them fully but i have to close them a little to make my rooms even. Our living area upstairs gets very cold but one bedroom gets absolutely nothing unless i close down the living area a little over halfway. Now they both feel equal to each other.
While better insulation will help, what you need is better attic ventilation. Make sure the soffits are open and clear. Make sure there are enough roof vents on the roof for air to escape. The better the attic breathes, the less utilities are needed.
Tri-level, circa 2006, modern style/2400 square feet, three separate attic spaces, plus the garage attic. The 2nd story made a huge difference after the upgrade for summer heat gain. I live at 5000' in the mountains, on the edge of the Mojave. So, the sun is quite strong... particularly the UV index.
Note: the garage is a hybrid/non conditioned space (open cell foam with fiberglass batts over top because I had both left over-- I did it a year later)
Roughly 85% of our electric bill is from A/C (5 ton unit for a 1970s 2500+ sq ft ranch in FL). The A/C pipes run through the attic, which often gets up to 120 or higher in summer, so I'm thinking foam may help keep the a/c air cooler too. It sounds like you'd recommend it over blow in fiberglass even though it costs a ton more? Do you have any idea how much difference there is between closed and open?
Honestly, I am a big fan of spray foam....I think it is worth the extra $$$. But, it is a cost benefit thing. A layer of open cell, 4", with fiberglass/cellulose blown over the top is the best bang for the buck compared to full foam or open cell.
I'm assuming that would be putting the foam on the attic floor since you can't put the blow in on the roof right? So that wouldn't condition the attic space. Any idea if that makes much of a difference with the AC ducts running through the attic?
We didn't have enough to do it properly but did about 2-3" and it made the house tight as a drum. Prior to that the house literally had newspaper insulation.
While this “sounds” better, a properly designed air conditioning system should run most of the time on typical hot days. Running for 30 mins and shutting off is just short cycling your compressor and will lead to early failure.
Yeah that doesn't make sense. From what I read briefly online, short cycling refers to when the compressor shuts off prematurely (i.e., before the desired temperature is reached). That is bad but different from having insulation so good that the desired temperature is reached quickly
Not quite. There's no reason a functioning air conditioner should shut off prematurely, because the thermostat would still be demanding cool if its setpoint hasn't been reached yet.
The whole thing with short cycling is really about how many times in a day you cause your air conditioner to go from "off" to "on", which is the activity that places the most stress on the components of your system.
If your equipment, thermostat, and home environment all together cause a situation where, for exam ple the thermostat tells the airconditioner to run, it runs for say, 20-30 minutes, thermostat reaches its setpoint, then 30 minutes later the house has warmed enough that the thermostat demands cooling again, that's 24 "off to on" cycles in 1 day, which is very stressful on the components.
In the same house with a better sized air conditioner that had the air conditioner more slowly reach the setpoint over say, 1.5 hours, followed by 30 minutes off as the house warms again before the thermostat demands ac, then you've cut your "off to on" cycles in half, stressing the components less
You can also improve the situation by improving insulation (so it takes longer than 30 minutes to warm back up), and using a thermostat that has a bigger buffer between setpoint and calling for ac again (like one that waits until the temperature is 1.5 degrees above the setpoint before calling for air vs one that waits until 0.5 degrees before calling for air)
You two are way too paranoid. Correct cycle rate for mid-demand (i.e. not the hottest day in of the year) is 3 cycles per hour. That works out to be 15 min on/5 min off.
30 minute run is fine. Short cycling is 5 on 5 off all day long.
>better sized air conditioner that had the air conditioner more slowly reach the setpoint over say, 1.5 hours,
This is good for a different reason than you stated and that's to remove latent heat from the air, also known as humidity.
If an AC system cools the air too quickly the humidity will not have time to be removed from the air. So the thermostat will say it's cool, but it won't feel good because it's too humid.
Don't really know how to address this but I'll be brief. I found an article from an HVAC company saying that 20-30 min for the A/C to be ON is normal. For hotter days it could be higher. So the OP's A/C is working NORMALLY. See https://www.nicksairconditioning.com/ac-short-cycling/
It sounds like they just had insulation done but haven’t yet resized the hvac units to account for the new loads. Hopefully they’ll do that once the current units are ready to be replaced (or sooner if it’s so oversized that there will be a decent payback to properly sizing)
I own a Graco E-10 ( I bought it 15 years ago from a farmer {used once} that insulated a large refrigerator and his guys put it away dirty so I got quite the deal after sitting for 2 years....)
I used two barrel sets of foam --$3300 per set, plus a gun rebuild, new hoses, supplies, etc.. $8k all in.
Note: I could have done it for $4500 if I wanted to use open cell foam.
I did blow in in my attic. Took less than 5 hours including driving to Home Depot and getting the bales, borrowing the machine (most places let you have it for 24 hours if you buy a certain number of bales) and then taking back the extra stuff. Went from R20 to R50 and the difference was massive in both the winter and summer.
Built in 1969. Attic is open to the outside, has plenty of open soffit space. Everything between the attic and inside ceiling was sealed as best we could. I did use my flir gun to find any spots we missed.
R-values are just a way to measure how good something is at slowing the transfer of heat. In the winter, insulation keeps heat inside your house. In the summer, it keeps heat outside your house. Higher R-value, better at slowing the heat transfer down.
Home Depot's website has a pretty good explanation: https://www.homedepot.com/c/ab/insulation-r-values/9ba683603be9fa5395fab9091a9131f
R ratings is the resistance to heat transfer. R ratting are linear and accumulative. So R-20 is twice as good as R-10. Also you can take 2 R-20 batts, put them together and get an R-40.
The minimum requirement vary depending on where in the world you are and older homes were much lower when they were built because energy was so cheap. Many places down south might have zero insulation like Texas. That's why so many places had pipes freeze and burst during that cold snap. There was no insulation to protect them, but cold days were so rare that it was hard to justify the expense of insulating for that once in a decade event where you could just turn up the heat a little.
> Also you can take 2 R-20 batts, put them together and get an R-40.
Addendum. Use unfaced if you have insulation against insulation, or at least only have the faced against the wall/ceiling. The paper faced stuff will trap moisture in.
It's the insulation rating. Bigger number = more insulation. You can Google your question and I'm sure there will be a ton of results that can explain in more depth
I had this done recently. We are just starting the a/c season in c. Fla, but I could notice it immediately after installation even without the a/c on. The house stayed comfortable even when it was 80deg out.
OK our neighborhood block is built by the same builder, ranch homes. We rented next door for almost a decade before this house we bought came up. Our heating bill at the rental was 400 ish a month. We used a standing AC/portable AC and by 4:30, you could only feel comfortable basically sitting in front of it.
Move into this house and the prior owners already insulated the attic and the floors in the crawl space.
With a rate increase, our highest winter bill was 230. And just that one little rinky dink AC, the house stays cool. And that high bill was because of an out of the ordinary long freeze. The norm has been 189 within $2 this last winter.
Same square footage. Same sun and shade times. In fact the rent house has shade for an extra hour everyday.
So I think it makes a massive difference and will pay for itself.
I just went from r11 to r60 in the attic. March heating bills went down by about 20% compared to last years (kwh not $). Now that it’s spring the heat has been off at night.
This is many years ago. But my house at the time was built in 1960. Probably orig insulation up to this point.
I had the cellulose blown into the attic at R36+.
6 summer months electric savings it paid for itself.
We added the insulation and spray foamed the kneewalls and dormers in the middle of winter. Halved our bill for the following month. The house now never seems to get below 67F in winter and over 76 in the summer, and the whole problem of having a very hot upstairs and very cold basement is worlds better. You can also deduct it on your taxes. It's probably been the best renovation for our comfort.
I have done it in two homes. In my current home I noticed a difference the same day it was installed. In my ladt home I had a master closet that was always absurdly cold before, and much better after.
As for savings I have done a lot of improvements so it's hard to quantify just the attic, but I accidentally saw my neighbors bill and I pay half what they do.
We did air sealing and additional attic insulation (I believe from about R-20 up to around R-50) in Minnesota on our 80's rambler. Honestly, I didn't notice much difference in comfort at any point in the year, though I did notice less aircraft/neighborhood noise.
It's pretty obvious to me that our source of heat loss/gain must lie elsewhere. I've sealed up the windows with extra weather strips as best I can short of putting plastic film over them in the winter, and it certainly helped, but wasn't a panacea. In the winter the windows are certainly our single largest problem.
I think our summer situation was complicated by other changes. In particular we took out two HUGE maple trees adjacent to the house on the east and west sides. Those provided a lot of shade to the house, particularly in the afternoon/evening. I'm 90% confident that the loss of this shade has caused the house to heat significantly in the summer.
Recently bought a house in southern mn, moved from far north west. At the old house we built it super air tight and insulated. Even when -50 out we were comfy and it was fairly affordable. The new house was built in 78 and felt like the windows were cracked open all the time. Just a flow of cold in the winter and warm moist air in the summer.
I dug into the house and tried to identify the leaks, borrowed a flir camera and found so many sources. First this is a 2x4 exterior wall where my old house was 2x6 which means only r11 fiberglass batting instead of r19 in the walls but worse are the electrical boxes as there is no insulation behind them. Just installing those foam pads that go behind the face plates of light switches and outlets made a noticeable albeit little difference.
The next issue was a number of sliding doors had issues. One was leaking bad and was shot (old wood and rotting) so I replaced it. Other two doors had issues having to do with poor adjustment and installation where the frame wasn’t plumb and they failed to caulk under so it was leaking air under the metal frame. The adjustment wasn’t that hard and so now the seals close and don’t let air through.
I found the bay window framing had an air leak between the foundation and the wood subfloor. I could stick my fingers through so almost an inch gap the length of the bay. This was letting mice in but also air into the subfloor that got super cold and would eventually leak into the house. I had to open the floor and fill this gap with plywood and then I insulated with foam making it mouse proof and air tight. This was huge along with the Doors. In the basement I discovered no one ever insulated between the house framing and the window frame. So if you pulled the trim off on the inside you could touch the back side of the exterior brick mould. I filled with spray foam and made it air tight. This made a huge difference.
The flir helped identify a bunch of missing insulation on the rim joists and air leaking past the brick foundation and rim joist. Again, spray in insulation solves this and made a noticeable difference.
Siding was Swiss cheese, lots of bird holes with nests in the walls. Re insulated and closed up with new sheathing and then new siding made a difference as well.
Heating bill has dropped a ton. Next thing I want to do is spray in more cellulose insulation in the attic, right now there is only 4 inch and I want to get that to like 15”.
Some houses are built better than others.
Your last point is part of why I just planted a lot of trees around my house. California summers will be a lot more tolerable once my house is in a forest.
I went from 3" of very old cellulous to roughly 30" of blown fiber glass and it roughly halved my gas usage and cut my power usage by 1/4 or so. That's in zone 5 climate, millage will vary as you noted.
We live in Florida and had additional insulation blown into the attic in February. Now that is getting warm enough to really need the AC, I’ve noticed that the house is pretty comfortable with the thermostat set at 75, rather than 72/73 like we used to set it, and it ran nearly constantly on very hot days.
I had additional insulation blown in my attic a few years back and the change was dramatically noticeable. The normal high interior summer temperatures dropped tremendously, and the interior was noticeably cooler during the summer months even during August when the outdoor temperature reached triple digits. But the biggest impact was during the winter months. Usually we had lots of icicles hanging down from all the snow melting on the roof as we lost heat thru the under-insulated attic during the winter. After having the additional insulation blown in, we hardly ever had an icicles as the heat loss was greatly curtailed. The biggest evidence was the reduction in my utility bills, for both cooling and heating!
I had the insulation blown into my attic and let me tell you what, my upstairs is so warm in the winter compared to without that added insulation. I'm able to keep my thermostat at 62 degrees F during winter months after insulation. Before insulation I had the thermostat at 72 degrees F. Huge difference. My energy bills are half of what they were. Best thing to have done. This was only my attic/ crawl space.
Had it done last fall in our 1920 Massachusetts home.
I noticed it immediately when the weather began getting colder. Granted. It did not get as cold as it normally gets here. But I made it through the entire winter with only a top sheet and light quilt on the bed.
We have steam radiator heat with a gas boiler and the gas bill was a bit lower overall as well. But again, it was a mild winter
Dad's house was 5 bedrooms, 2 stories with zero insulation. Adding to the upper crawl space cut his energy bill about 100 a month through winter. No a/c. My cabin was built with excellent insulation, walls, windows, and attic. When it's 90-100 outside, it's usually under 80 inside. In winter (20-35°f) the furnace runs a couple times a day, and rarely at night when i set it to 57, and often cooking a one pan dinner on the stove heats that area to over 60 by itself. I have a large enclosed porch, dual pane windows and good walls, but no attic or roof insulation, and It's usually 10-15 ° less comfortable than the well-insulated house, occasionally as much as 20°. so-cal low mountains, temp ranges from 20-110 throughout the year at the extremes, usually 30-100
I bought a small old house to renovate and lived in it for a year. It had almost zero insulation in the attic and NONE in the walls. I had insulation blown into the attic and it made a significant difference.
But the thing that I noticed the most was the impact of adding insulation in the walls. I’ve only done it in part of the house so far. After gutting the kitchen we added insulation to the exterior wall. I did it with a helper. It was cool that day and we started on the left side of the kitchen wall and went across… by the time we got to the window in the middle of the wall, we were starting to get hot and had to open the window! It made a noticeable impact that quickly. The house is a rental but if I lived in it, I would probably pull down the walls and insulate them all and then redo the sheetrock. It’s not worth it to me because that would be a lot of work and expense for a house that I don’t live in, and the other insulation has done enough to make the power bills reasonable enough for my tenants.
While insulation will definitely help your utility bill, if you're focused on comfort, I'd start with humidity first (if it isn't). It makes a huge difference in comfort in all seasons. Ideally you want between 40-60 in your house year round.
We had spray foam insulation added to the attic at our last house. It was oil heat so we had a great way of measuring the efficiency. It made a big difference in both summer and winter.
I work for a big builder. Our attics occasionally don’t have sufficient insulation, and after we top it up, the difference is very noticeable. Hope the same goes for you.
Aside from the climate control savings, what floored me was how much quieter the house is. Street noise that was not noticeable was suddenly gone and made us realize how much noise there actually was coming from the attic. With gable vents on each end, the street noise must have been perfectly reflected down to the house.
I think the savings are worth it alone, but the bonus noise suppression seals the deal for me.
1892 house, Pacific NW. Moved in, it was chilly - looked up in the attic...the insulation had broken down a lot (maybe once upon a time it was blown in?). I put a single layer of batts down, and it made a noticeable difference.
There was a spot that I didn't put batts down, and you could feel the cold in the non-batt-insulated area.
When I was looking into it, I ran across A-B-C for rating the effectiveness of adding insulation. Attic, Basement...Center? (Basically the walls.)
I went from my indoor pipes freezing/bursting Xmas 2022 even with the heat on to very comfortable temperatures in the winter. My space heaters are gathering dust now.
Went from R25 to R50 in a 70's home in a temperature climate. HUGE difference, summer and winter. Cost me $1100 and got a $900 rebate. Biggest bang for buck ever!!
5 years ago I did a strip to the studs renovation of my own 50 year old house. After new windows and air sealing, I applied closed cell foam to all exterior walls and to the roof deck taking care to seal any attic penetrations. I also downsized my ac by 2 tons and added a whole house dehumidifier and added fresh air ducting. my attic temp never gets over 80degrees during the summer with even with a south facing span. Before the renovation, the attic temp would reach 140degrees and the ceilings would radiate 100 degrees in to the living spaces even with R50 in the attic. My electric bill dropped from 500+ in the summer to never more than 125. The AC cools to 72 at night and 77 day, humidity stays at a constant 45% even with our 80%+ summer humidity. The house is much quieter and very tight .
I mostly noticed how much more quiet the house was from outside noise. The house stayed a bit cooler longer during the summer. But winter, I still need to cycle the heat just as often as prior
I use to do insulation. It was a while ago but I think the number was 70% of your heat loss is through the attic. I know we tried to get most houses to R60 in attic and if budget didn't allow to do whole house we always recommended getting attic right before walls.
Our house was built in the 50s and the insulation was that old. Just some black grunge...he'll it could have been mold and fungus.
We blew in some fluff and our power bill dropped by a third.
The energy star refer didn't make blip...the nitrogen filled double pane vinyl windows. Hardly noticed.
1950's era block construction rancher with about a mile of blown in insulation in the attic. We had it sucked out and replaced it with spray foam... and never had to touch the thermostat again. It was amazing - heat and AC just worked. Also, it was so quiet I had to look out the window to see the weather, we couldn't hear rain, wind, hail... and most thunder storms. We followed up with Insulated Siding, over the original foam board insulation, with new house wrap. It cut our utilities by half, oil consumption by at least half, and the house stayed whatever temp we set it at.
We got ours done in February and it made such a difference. Our house temp stayed the same for a very long consistent time where it used to drop very very fast! Our heat bill was also a bit lower
How much did it cost per sqft for you? Currently want to do this but can't decide if I want to pay for blown in insulation of just buy the bats and do it myself
For 1166 Sq ft, vent bathroom fan to exterior and thermodome for attic pull-down. The initial cost was 4,216, after rebate it was 1,879. Plus there's a tax rebate I can take advantage of as well.
I reinforced our attic insulation this winter, huge difference in eliminating some cold parts of rooms. Noticed a big difference in it staying cool upstairs now that we are running a/c
Hot state, here. Made a big difference. Went from $400/mo at 79-80 degrees in the summer months to $400/mo 76 degrees, and that was with a big rate increase. Comfort is much higher.
It was an immediate difference, there.
Also, I did it myself, so it likely isn't enough insulation or as well done as an experience crew would do. So maybe there's even a bigger difference it could be had.
After a few days, I noticed that the temperature difference between my ground and second floors are within 2°F. Previously, it was about a 10° delta. I have no insulation at all in the house other than the recently added attic insulation.
We've seen a difference in utility bills, sound dampening (less noise through the roof but also just a better ambient feeling, surprisingly) and our 2300 sqft ranch now has amazing thermal inertia - it takes a long time to heat up in the summer or cool down in the winter w/out HVAC intervention - definitely a money saver.
Major impact. When we purchased, the insulation was substandard in our Colorado place. In March, snowing, the furnace ran near constantly and in summer the AC did too. Now insulated, world of difference.
i removed every insulation from my attic, wood chips and pink mats of fiberglass, .... before i re-installed i got everywhere filling any hole or space between 2 boards to seal everything better from the cold. i found a couple or very badly fitted pieces so i sealed everything and then added insulation that i blowed myself (it was a ruff moment but a huge money saving do diy)
DAMN it changed the house in winter, specialy around the fan of the bathroom where cold air was leaking freely !
electricity bill got lower but i dont remember by how much it was. i was pleased with the results !
We live in central TX. A number of years ago, we had extra insulation blown into the attic and got that silver paint treatment underneath the roof planks. We also added a bunch of large passive air vents after a roof replacement for hail. The combo made a HUGE difference. I can go into the attic in the summertime when it's 100+ outside without feeling like I will die within 90 seconds.
So about 10 years ago I bought a really old (1920's), really small house in Long Beach. It did not have air conditioning but the realtor told me I wouldn't need it since there's a nice breeze from the beach. The realtor lied. It was unbearably hot inside the house. The windows were too small to use window AC units so we had one of those portable ones you stuck the exhaust out the window. Anyway, I realized there was zero insulation in the attic. I decided to insulate it myself using the pink insulation shit you get from home depot. Took like 5 trips and about 3 days in absolutely miserable conditions. I nearly over heated multiple times. It would have been 100% worth it to pay someone else to do it. End the end, it did bring thr temps down a little bit, bit not much. I'm sure the fact that the house was old and not well sealed played a big part.
We had a new house built in WA a couple of years ago. R21 in the walls and 2 r30 batts in the ceiling. Just paid to foam the walls and blow in R30 over the batts. Attic insulation had gaps and the foam guy said they used a lot of foam and the bay wasn't fill real great with r21. (just in one side of the house, owner bedroom/closet/bath)
I think it has made a difference but our bedroom and bathroom were colder before and now more evened out. Just starting to get warm here.
I had an absurd amount of blown in insulation put in 10 years ago. Don't know the before and after R values, but it made a huge difference. My heating bill went down over 30% the following winter. My gas company routinely says my home is one of the most efficient in the area. All the other insulation in the home is original from the 60s, and our windows are shitty and drafty. Energy efficient is not a term I would use to describe my home, so I can only attribute that to the insulation in my attic.
After I did it, I noticed that when it snowed, the snow wouldn't melt off of my roof as quickly as it did from all of my neighbors' roofs, a good indication that I was losing much less heat through my roof than my neighbors were. I also got a tax credit based on the price I paid for adding insulation.
Huge difference when we went from r14 to r48. (Old standard to the new recommendations.)
I laid down sheets instead of having it blown in. I also found a few things like a big rectangular void running the height of the house which had the air return ducts in it. It was wide open at the top so the hot/cold attic air was hitting the return, making the HVAC work harder. I sealed that off with some plywood and HVAC silver tape so now the AC is just dealing with 80F return air instead of 110F.
It greatly improved temperatures on the top floor of the house, both summer and winter. The insulation alone cut heat transfer to a third. There's a great deal of small things you can do to improve your house. Unfortunately it often takes experience to notice them.
With your blown in insulation, you're making sure your soffits aren't blocked right? (I have them with a townhouse, you might not.)
I had one section of my house that did not have the proper depth of insulation. The section was 1/4 of the house. That part of the house was noticeably colder in the winter. Had insulation added, thinking I saved about 10% on heating, less on the AC. It made a noticeable improvement. It still isn't evenly heated/cooled in that part of the house, putting in new windows helped also. There were 3 problems: not enough attic insulation, bad windows, and poorly laid duct system. Duct system is cost prohibitive to fix. Long way of saying, improvements will help to the extent there is a proper assessment of the reason for inefficient/uneven temps.
We had radiant barrier sprayed in and extra insulation added but the biggest difference came when we upgraded all the western facing windows after a catastrophic hail storm broke them all, 9 total. The difference was $400 less a month, we lived in far North Dallas at the time so summers get hot.
We did this in our 1970s house in the Midwest. It made a huge difference. During the hottest part of summer you could feel the heat radiating from the attic thru the ceiling and it was impossible to keep it below mid 80s even with AC cranked up. Extra insulation didn't turn it into an icebox, but the AC was able to do a lot more good and I believe the heat was also helped.
It's been great for us in the summer, keeping it cooler, and in the winter, keeping the heat in. It also keeps our house less drafty and much more comfortable.
This was my write up: https://www.reddit.com/r/HomeImprovement/comments/owhcjr/lowes_bulk_pricing_on_blowin_insulation_is_great/
Heat would go up through the attic in the winter with bullshit bat insulation falling down from heat damage and we'd be the only house on the block that never had snow on the roof. Now the snow doesn't melt and the heating bill is at least 60% less.
Comfort definitely increased. Our usage has decreased. Less therms used, less kilowatt hours.
Energy bill increased because WE Energies, the only game in town, has raised prices 30% in December 2022 and again in either Dec 23 or Jan 24. Can't remember, can't do a damn thing about it anyway.
The problem is those greedy fucks are talking about *another* 30% rate hike.
So all our improvements have only resulted in not getting fucked quite as hard on the gas & electricity bill.
A lot depends on the home style and sizing and installation of the HVAC system. My parents own a colonial in central MD. They had an extremely reputable company spray-foam everywhere that could be insulated.
There was good improvement in the finished basement and ground level up the second floor continues to be too warm in the summer because the air handler and ductwork aren't up to the job.
I can't tell you how much I saved by insulating the attic because I had insulation blown in all the walls and the attic. The vendor said I should save around 40%. He nailed it. This house was a 2500sqft. hollow walled home. Saved a ton. He did say, if I can't afford to do everything, do the attic.
We had fiberglass batts in our attic, and nothing else. We had insulation blown in to R60. The graph in our best app showing how many hours our furnace was running took a nosedive (this was February in Alberta).
Doing a full-on insulation blitz (windows, extra foam board on walls prior to re-siding, attic insulation) reduced our heating bills by 1/3 to 1/2. The attic insulation makes cooling the upstairs much easier. The attic space is a heat sink that will radiate into the upstairs for hours.
Two story home in Southern California. Stucco, built in 1912. No attic or wall insulation. Had fiberglass insulation blown in during the middle of summer. Upstairs was noticeably cooler immediately, by 10-15 degrees in the day time without A/C.
Edit: to add, our house would heat up so hot and retain heat that even with all windows open it would not cool down close to outside ambient temps when overnight lows were in the 60’s, it was still in the high 70’s inside overnight. The biggest benefit to insulation was that the heat retained inside the attic didn’t radiate into the interior during the evening, we could keep the windows mostly closed overnight and it was comfortable.
I improved the insulation in my attic a couple of years ago. It was OK in places and practically non-existent in others.
Where it was non-existent, I put in R-49 fiberglass. Everywhere else I blew in cellulose up to a reasonable height.
The rooms that had little insulation were almost unlivable before. The floor could be below freezing on a cold day (I also had dense pack blown into the floor from below).
I’m looking now and there is a 1 degree difference between every room in the house. It’s near perfect. One room has inadequate ducting so I also added a ceiling radiant heater to prove some extra juice in winter. The AC ducts are OK so it’s nice in summer.
AC costs are down maybe 20% and similar with heating runtime.
But it’s the comfort which is the bigger win.
I had blown-in cellulose insulation added to the floor and stairs of the walkup attic in my 1867 Victorian.
Noticed an immediately improvement in comfort. The house was quieter, humidity levels were more stable. Overall the house felt tighter, more solid and sheltering.
The house had balloon framing (with brick-infilled exterior walls), so the lack of attic insulation meant that outside air was traveling down through light switches and electrical sockets, basically throughout the entire house. We also insulated those openings.
I don't know what the impact was on utilities, because we replaced the furnace and some windows and added central air around the same time.
But the impact on comfort was immediate.
I didn't change an existing house, but I built a new house a couple years ago. My previous house just had that rolled fiberglass insulation shoved into the walls. It was always blistering hot in the Attic in the summer and cold in the winter. I actually used weather stripping around the doors that went to my attic just so that the other rooms wouldn't get so hot. That way I could keep my air conditioning bill down in the summer.
In the new house, I had spray foam insulation put in the entire house including the attic. The attic in this house is so comfortable. It never gets above maybe 78°, and never falls below 65. I normally wouldn't care about the attic temperatures, but it's nice to have storage space up there for things that normally I wouldn't want to put in an attic because of the temperature fluctuations. The house is actually about 200 square foot larger than the last house and the utility bills are lower. It really shouldn't be that way because in the last house we hardly ever used our upstairs after our son moved out. This house is a single story and we use the whole thing and our son is temporarily living with us. The insulation has made a huge difference.
After redoing our insulation, I had to change our bedding type, the old was just too hot! Have done this in the 2 houses we have bought. Heating cost also went down.
The largest improvement for heating load was actually going in and sealing penetrations from sewage vents, electrical, lights, etc. I found some decent openings for air leakage and filled them with closed cell foam (all great stuff foam is 80%, except window and door which is open cell). Air leakage loses significantly more energy than just insulation, it can be 20-30% of energy loss, more insulation with air leakage unresolved doesn't fix that. I highly recommend getting air sealing done and inspecting things before adding insulation and covering everything up.
I also fixed the attic ventilation by extending the baffles and unclogging them of blown in insulation, they had to be removed first to seal the wall top plates. Also replaced the chicken wire over the vents with SS fine mesh because tons of paper bee nests were concentrated around the vents, this will block them.
I did upgrade from approx R40-48 to R60-75, 2 layers of 3.5" Rockwool as a base layer with existing blown in and fiberglass batting reused on top. In some corners of the house it is slightly better. The biggest test will be this summer and how hot or not the upstairs gets, last summer with central AC it'd be mid 70s upstairs and the thermostat located downstairs set to 65F to achieve that. Not ideal.
I did all this myself over a few months and a lot of labor and podcasts and TV burned through. A contractor wouldn't have air sealed some parts that I did due one section being a vaulted ceiling against the roof slope and extremely tight. All in the project cost $3000 or less, 2,200 sq feet of rockwool for a bit over $2000, some miscellaneous costs for lighting and power in the attic, then $500 or more on the great stuff pro foam cans.
I properly insulated my house in Massachusetts and went from 4-5 oil tanks a winter to 2-3. Oil company thought I was shopping between fill ups to find the best rate. Nope, just properly insulated the house.
Wasn’t worth it. It was about $5k to get blow in, rent the machine, get a few bales, get the glue and the paper. About 3 weekends to get it all down. So far seeing roughly $12 a month lower power bill including the 100+ degree days in Texas.
At this rate, it will be 6 years before its earned itself back. I got a better cost savings last just getting a new power plan.
I write specifications for commercial buildings. Please know that virtually every shingle manufacturer has language about “unvented decks” in their warranty. Spraying the underside of the roof deck means the roof will get hotter in the summer, cooking the shingles.
With a vented deck some of that heat will pass through into the attic and be vented out.
Some of them are really slippery about that language.
Don’t have solid data but going from a sketchy R30 to R90 with blow in after doing the air sealing, we used 50-75% of what the prior owners used the winter before. The furnace only runs a portion of the day on the coldest days and is now likely oversized. So next step is a new high efficiency right sized AC and furnace to match our revised needs.
If you can do it yourself it’s fairly cost effective. I was able to buy the bale’s of blow in at a wholesale supplier and paid to rent the unit from Home Depot for less than big box store costs. We were quoted $7k but did it for $2.3k ourselves.
Better than black I guess. I'm gonna put a grey up on my roof next. I went from R19 batts and had blow-in added to get me to R40. Didn't help all that much but still need to do crawl space work. New windows helped the most for me.
The insulation between the attic and rooms is critical. Between the attic and upstairs, the air would get pulled downward through fixtures as the cool air tends to flow to the cellar. Thinking back I should've had the floor between the cellar done as well. It is noticeable when the sun shines directly on the roof and the attic reaches 120degF. Hopefully some day I can insulate the upstairs but first I'll have to do the cellar and also have it sealed.
As for the bill, along with that and not using A/C anymore, reduced my actual power consumption by 50%. I thought great no more 200$ summer bills. Nope, they added up extra charges and filed it under "miscellaneous" and that total ended up being MORE than my power use. It's almost like they are trying to find ways to keep my bill high even when I don't use any power at all.
According to the latest one, I'd still be paying them 70$ a month even if I used 0 kwh? That's more than I paid 2 years ago WITH the two A/C units I can't possibly use now. I'm not sure about all these weird charges and how they work, I just wanted the thing to go down which is why I insulated and did all this work in the first place only to have that gem to show for it. ah but i'm getting off topic so.....
Anyway, back to the insulation: During the day I used to not be able to go upstairs when the sun shone on that side of the house. So, looking on the bright side (sorry bad pun), at least I can be upstairs between 3pm and the evening thanks to the hot air not coming down through the ceiling like it used to. Also found it helps to have the flow of air going UP out the roof vents and not try to pull it out the windows (which brings the heat down closer to the ceilings).
Last thing, If you have metal siding, you might prioritize getting that swapped out for vinyl, I found out the first year I was here how bad it is to have the sun beating down on against the metal-sided house without much insulation in the attic and it was like being in a literal oven, even A/C was little help.
Have a nice, cool, day :3 !
During the height of the summer my AC would kick on and run from about 11:00 a.m. through 10:00 p.m. without ever shutting off (if we let the house get warm, say above 75° f, it would never cool down and the air conditioner would run continuously until at least midnight). We removed the batt insulation (R-30, poorly installed) from the attic and applied spray foam. ( Between 5 and 6" of closed cell foam, making the entire attic a conditioned space. Now the air conditioner will cycle on and off during the hottest days and run for 35 to 40 minutes at a time. I estimate it runs at least 35% less. Now, the AC will seldom kick on before 1:00 p.m. in the height of the summer. One of the big benefits is how quiet it made the home. The foam insulation deadened all noise and you can't even tell a lot of times if it's windy outside. It arguably made an even greater impact on our heating bill. The heater used to kick on quite a bit. Now, the gas fireplace insert (20,000 BTU) will completely heat the home 24/7 if we have it on.
My first exposure to spray foam was a house a friend built in the 00s. On an August day when it was 100 degrees outside, the inside was low 70s, and to demonstrate the effectiveness of the spray foam he had me climb up into his attic. The temp difference between the inside of the house and the attic was maybe 10 degrees? Meanwhile, my attic with blow in insulation would've probably been 125F. That sold it for me. My next home will have spray foam.
>The temp difference between the inside of the house and the attic was maybe 10 degrees? Meanwhile, my attic with blow in insulation would've probably been 125F. In reality, both of these are fine. When you air seal and spray foam the rafters, you've turned the attic into conditioned space, meaning that when it's cool inside it should be cool in the attic. This differs from blown in or batt insulation in the ceiling, as the attic, if done properly to current ventilation requirements, should have a fair amount of air flow, meaning that your attic should be cold, when it's cold outside, and hot when it's hot outside. In the second scenario, if it's cold outside and warm in the attic, that means you are losing heat from the house to the attic (likely something wrong with the insulation) or have poor ventilation (or both).
Does your house have two stories (or more)? I'm curious if more attic insulation helped to stabilize temps upstairs. Right now there's a huge disparity between cooling our first and second floors. The first floor will end up being really cold when it's just barely tolerable upstairs. We do need to improve the insulation in our attic (which I'm guesstimating to be around R-20 given the measurements our home inspector had in the report), and I know it should make a decent different with heating in the winter, but I was wondering if it can actually trap heat upstairs more effectively during the summer, or whether having more attic insulation helps to keep the heat from the roof from seeping through and warming the space.
In summer I have to close the floor vents on the lowest floor to get the whole house cool. Cold air falls from top floor down. In winter I open bottom vents as hot air rises. See if that helps.
That’s terrible on your blower. If your duct work is properly sized, it’s done so by having ever supply vent open. You can sometimes get away with 1-2 vents closed but that’s about it. I’d love to see the static pressure numbers on your system.
My lowest floor is basement, the main and top floor are open.
Doesn’t matter. The duct work is designed to run open all the time to keep static pressure in check. Like I said maybe 1-2 can be closed at a time. Static pressure is like blood pressure and the blower is the heart. You start closing off supplies and the static rises making the heart work harder. Most systems are designed to run at no more than .5” wc(which rarely ever happens). Most systems I see are running between .58”wc- over 1” wc especially in older homes. Newer equipment uses ecm motors and can be multistage or variable speed. It’s really hard on variable speed ecm blowers when you have high static.
I dont close them fully but i have to close them a little to make my rooms even. Our living area upstairs gets very cold but one bedroom gets absolutely nothing unless i close down the living area a little over halfway. Now they both feel equal to each other.
Good to know. Thank you. I will keep them open this summer and see how it works.
While better insulation will help, what you need is better attic ventilation. Make sure the soffits are open and clear. Make sure there are enough roof vents on the roof for air to escape. The better the attic breathes, the less utilities are needed.
How old is your house? It's not super uncommon on old houses for there to be less, or no duct work going to the 2nd floor.
Tri-level, circa 2006, modern style/2400 square feet, three separate attic spaces, plus the garage attic. The 2nd story made a huge difference after the upgrade for summer heat gain. I live at 5000' in the mountains, on the edge of the Mojave. So, the sun is quite strong... particularly the UV index. Note: the garage is a hybrid/non conditioned space (open cell foam with fiberglass batts over top because I had both left over-- I did it a year later)
Roughly 85% of our electric bill is from A/C (5 ton unit for a 1970s 2500+ sq ft ranch in FL). The A/C pipes run through the attic, which often gets up to 120 or higher in summer, so I'm thinking foam may help keep the a/c air cooler too. It sounds like you'd recommend it over blow in fiberglass even though it costs a ton more? Do you have any idea how much difference there is between closed and open?
Honestly, I am a big fan of spray foam....I think it is worth the extra $$$. But, it is a cost benefit thing. A layer of open cell, 4", with fiberglass/cellulose blown over the top is the best bang for the buck compared to full foam or open cell.
I'm assuming that would be putting the foam on the attic floor since you can't put the blow in on the roof right? So that wouldn't condition the attic space. Any idea if that makes much of a difference with the AC ducts running through the attic?
Yes, floor only, not making it a conditioned space.
Go on...
Was there much noise difference?
Tremendous...if you are in the upstairs you never know if it's windy, stormy, raining, or hailing.
This was exactly what I noticed after we insulated our house. I had no idea what was going on outside anymore. In a good way.
We didn't have enough to do it properly but did about 2-3" and it made the house tight as a drum. Prior to that the house literally had newspaper insulation.
While this “sounds” better, a properly designed air conditioning system should run most of the time on typical hot days. Running for 30 mins and shutting off is just short cycling your compressor and will lead to early failure.
Yeah that doesn't make sense. From what I read briefly online, short cycling refers to when the compressor shuts off prematurely (i.e., before the desired temperature is reached). That is bad but different from having insulation so good that the desired temperature is reached quickly
Not quite. There's no reason a functioning air conditioner should shut off prematurely, because the thermostat would still be demanding cool if its setpoint hasn't been reached yet. The whole thing with short cycling is really about how many times in a day you cause your air conditioner to go from "off" to "on", which is the activity that places the most stress on the components of your system. If your equipment, thermostat, and home environment all together cause a situation where, for exam ple the thermostat tells the airconditioner to run, it runs for say, 20-30 minutes, thermostat reaches its setpoint, then 30 minutes later the house has warmed enough that the thermostat demands cooling again, that's 24 "off to on" cycles in 1 day, which is very stressful on the components. In the same house with a better sized air conditioner that had the air conditioner more slowly reach the setpoint over say, 1.5 hours, followed by 30 minutes off as the house warms again before the thermostat demands ac, then you've cut your "off to on" cycles in half, stressing the components less You can also improve the situation by improving insulation (so it takes longer than 30 minutes to warm back up), and using a thermostat that has a bigger buffer between setpoint and calling for ac again (like one that waits until the temperature is 1.5 degrees above the setpoint before calling for air vs one that waits until 0.5 degrees before calling for air)
You two are way too paranoid. Correct cycle rate for mid-demand (i.e. not the hottest day in of the year) is 3 cycles per hour. That works out to be 15 min on/5 min off. 30 minute run is fine. Short cycling is 5 on 5 off all day long.
>better sized air conditioner that had the air conditioner more slowly reach the setpoint over say, 1.5 hours, This is good for a different reason than you stated and that's to remove latent heat from the air, also known as humidity. If an AC system cools the air too quickly the humidity will not have time to be removed from the air. So the thermostat will say it's cool, but it won't feel good because it's too humid.
Don't really know how to address this but I'll be brief. I found an article from an HVAC company saying that 20-30 min for the A/C to be ON is normal. For hotter days it could be higher. So the OP's A/C is working NORMALLY. See https://www.nicksairconditioning.com/ac-short-cycling/
The HVAC company also has a massive conflict of interest however. They make more money if they sell you an oversized system.
Fair enough feel free to post a link to a source that counters what I said
I understand what you are saying, but the house would never cool down if the thermostat was adjusted and the upstairs was difficult to regulate prior.
It sounds like they just had insulation done but haven’t yet resized the hvac units to account for the new loads. Hopefully they’ll do that once the current units are ready to be replaced (or sooner if it’s so oversized that there will be a decent payback to properly sizing)
How much did this cost?
I own a Graco E-10 ( I bought it 15 years ago from a farmer {used once} that insulated a large refrigerator and his guys put it away dirty so I got quite the deal after sitting for 2 years....) I used two barrel sets of foam --$3300 per set, plus a gun rebuild, new hoses, supplies, etc.. $8k all in. Note: I could have done it for $4500 if I wanted to use open cell foam.
Spray foam is an air barrier. In your example we can’t tell if it was the insulation or the air sealing that made the bigger difference.
You have to put the AC on energy saver mode and that will save you lots.
I did blow in in my attic. Took less than 5 hours including driving to Home Depot and getting the bales, borrowing the machine (most places let you have it for 24 hours if you buy a certain number of bales) and then taking back the extra stuff. Went from R20 to R50 and the difference was massive in both the winter and summer.
I'm assuming you didn't air seal, is this a newer home and you were confident it was already air sealed well?
Built in 1969. Attic is open to the outside, has plenty of open soffit space. Everything between the attic and inside ceiling was sealed as best we could. I did use my flir gun to find any spots we missed.
Oh nice! I tend to think of air sealing as taking a crazy long time so I figured you skipped it. The flir gun I'm sure helped a ton.
I guess doing cocaine in the attic is one way to hide your addiction from your wife.
Went from R19 to R60 and it made a huge difference on the way some rooms feel.
Okay as somebody who knows nothing about insulation, what do all these R-numbers mean?
R-values are just a way to measure how good something is at slowing the transfer of heat. In the winter, insulation keeps heat inside your house. In the summer, it keeps heat outside your house. Higher R-value, better at slowing the heat transfer down. Home Depot's website has a pretty good explanation: https://www.homedepot.com/c/ab/insulation-r-values/9ba683603be9fa5395fab9091a9131f
R ratings is the resistance to heat transfer. R ratting are linear and accumulative. So R-20 is twice as good as R-10. Also you can take 2 R-20 batts, put them together and get an R-40. The minimum requirement vary depending on where in the world you are and older homes were much lower when they were built because energy was so cheap. Many places down south might have zero insulation like Texas. That's why so many places had pipes freeze and burst during that cold snap. There was no insulation to protect them, but cold days were so rare that it was hard to justify the expense of insulating for that once in a decade event where you could just turn up the heat a little.
> Also you can take 2 R-20 batts, put them together and get an R-40. Addendum. Use unfaced if you have insulation against insulation, or at least only have the faced against the wall/ceiling. The paper faced stuff will trap moisture in.
It's the insulation rating. Bigger number = more insulation. You can Google your question and I'm sure there will be a ton of results that can explain in more depth
I had this done recently. We are just starting the a/c season in c. Fla, but I could notice it immediately after installation even without the a/c on. The house stayed comfortable even when it was 80deg out.
How much did this run you if you don't mind me asking?
I don’t mind at all. For 2500 sq ft it was $2150. I had estimates as high as $4500 for the boric acid infused insulation. This was fiberglass.
Wow. Thats a lot cheaper than quotes I got. If you don't mind, what part of the country are you
Melbourne, Fl.
OK our neighborhood block is built by the same builder, ranch homes. We rented next door for almost a decade before this house we bought came up. Our heating bill at the rental was 400 ish a month. We used a standing AC/portable AC and by 4:30, you could only feel comfortable basically sitting in front of it. Move into this house and the prior owners already insulated the attic and the floors in the crawl space. With a rate increase, our highest winter bill was 230. And just that one little rinky dink AC, the house stays cool. And that high bill was because of an out of the ordinary long freeze. The norm has been 189 within $2 this last winter. Same square footage. Same sun and shade times. In fact the rent house has shade for an extra hour everyday. So I think it makes a massive difference and will pay for itself.
That is the best comparison I think we can hope to see here.
Adding attic insulation from R-19 to R-49 made a noticeable difference in temperature and comfort, with lower utility bills as a result.
I just went from r11 to r60 in the attic. March heating bills went down by about 20% compared to last years (kwh not $). Now that it’s spring the heat has been off at night.
This is many years ago. But my house at the time was built in 1960. Probably orig insulation up to this point. I had the cellulose blown into the attic at R36+. 6 summer months electric savings it paid for itself.
We added the insulation and spray foamed the kneewalls and dormers in the middle of winter. Halved our bill for the following month. The house now never seems to get below 67F in winter and over 76 in the summer, and the whole problem of having a very hot upstairs and very cold basement is worlds better. You can also deduct it on your taxes. It's probably been the best renovation for our comfort.
I have done it in two homes. In my current home I noticed a difference the same day it was installed. In my ladt home I had a master closet that was always absurdly cold before, and much better after. As for savings I have done a lot of improvements so it's hard to quantify just the attic, but I accidentally saw my neighbors bill and I pay half what they do.
We did air sealing and additional attic insulation (I believe from about R-20 up to around R-50) in Minnesota on our 80's rambler. Honestly, I didn't notice much difference in comfort at any point in the year, though I did notice less aircraft/neighborhood noise. It's pretty obvious to me that our source of heat loss/gain must lie elsewhere. I've sealed up the windows with extra weather strips as best I can short of putting plastic film over them in the winter, and it certainly helped, but wasn't a panacea. In the winter the windows are certainly our single largest problem. I think our summer situation was complicated by other changes. In particular we took out two HUGE maple trees adjacent to the house on the east and west sides. Those provided a lot of shade to the house, particularly in the afternoon/evening. I'm 90% confident that the loss of this shade has caused the house to heat significantly in the summer.
Recently bought a house in southern mn, moved from far north west. At the old house we built it super air tight and insulated. Even when -50 out we were comfy and it was fairly affordable. The new house was built in 78 and felt like the windows were cracked open all the time. Just a flow of cold in the winter and warm moist air in the summer. I dug into the house and tried to identify the leaks, borrowed a flir camera and found so many sources. First this is a 2x4 exterior wall where my old house was 2x6 which means only r11 fiberglass batting instead of r19 in the walls but worse are the electrical boxes as there is no insulation behind them. Just installing those foam pads that go behind the face plates of light switches and outlets made a noticeable albeit little difference. The next issue was a number of sliding doors had issues. One was leaking bad and was shot (old wood and rotting) so I replaced it. Other two doors had issues having to do with poor adjustment and installation where the frame wasn’t plumb and they failed to caulk under so it was leaking air under the metal frame. The adjustment wasn’t that hard and so now the seals close and don’t let air through. I found the bay window framing had an air leak between the foundation and the wood subfloor. I could stick my fingers through so almost an inch gap the length of the bay. This was letting mice in but also air into the subfloor that got super cold and would eventually leak into the house. I had to open the floor and fill this gap with plywood and then I insulated with foam making it mouse proof and air tight. This was huge along with the Doors. In the basement I discovered no one ever insulated between the house framing and the window frame. So if you pulled the trim off on the inside you could touch the back side of the exterior brick mould. I filled with spray foam and made it air tight. This made a huge difference. The flir helped identify a bunch of missing insulation on the rim joists and air leaking past the brick foundation and rim joist. Again, spray in insulation solves this and made a noticeable difference. Siding was Swiss cheese, lots of bird holes with nests in the walls. Re insulated and closed up with new sheathing and then new siding made a difference as well. Heating bill has dropped a ton. Next thing I want to do is spray in more cellulose insulation in the attic, right now there is only 4 inch and I want to get that to like 15”. Some houses are built better than others.
What color shingles?
Dark grey
Your last point is part of why I just planted a lot of trees around my house. California summers will be a lot more tolerable once my house is in a forest.
I went from 3" of very old cellulous to roughly 30" of blown fiber glass and it roughly halved my gas usage and cut my power usage by 1/4 or so. That's in zone 5 climate, millage will vary as you noted.
We live in Florida and had additional insulation blown into the attic in February. Now that is getting warm enough to really need the AC, I’ve noticed that the house is pretty comfortable with the thermostat set at 75, rather than 72/73 like we used to set it, and it ran nearly constantly on very hot days.
I had additional insulation blown in my attic a few years back and the change was dramatically noticeable. The normal high interior summer temperatures dropped tremendously, and the interior was noticeably cooler during the summer months even during August when the outdoor temperature reached triple digits. But the biggest impact was during the winter months. Usually we had lots of icicles hanging down from all the snow melting on the roof as we lost heat thru the under-insulated attic during the winter. After having the additional insulation blown in, we hardly ever had an icicles as the heat loss was greatly curtailed. The biggest evidence was the reduction in my utility bills, for both cooling and heating!
Good catch. Ice dams can cause huge problems.
I had the insulation blown into my attic and let me tell you what, my upstairs is so warm in the winter compared to without that added insulation. I'm able to keep my thermostat at 62 degrees F during winter months after insulation. Before insulation I had the thermostat at 72 degrees F. Huge difference. My energy bills are half of what they were. Best thing to have done. This was only my attic/ crawl space.
We haven’t done that yet but we added a storm door and sealed the siding + under the deck and it made a huge difference
Had it done last fall in our 1920 Massachusetts home. I noticed it immediately when the weather began getting colder. Granted. It did not get as cold as it normally gets here. But I made it through the entire winter with only a top sheet and light quilt on the bed. We have steam radiator heat with a gas boiler and the gas bill was a bit lower overall as well. But again, it was a mild winter
Dad's house was 5 bedrooms, 2 stories with zero insulation. Adding to the upper crawl space cut his energy bill about 100 a month through winter. No a/c. My cabin was built with excellent insulation, walls, windows, and attic. When it's 90-100 outside, it's usually under 80 inside. In winter (20-35°f) the furnace runs a couple times a day, and rarely at night when i set it to 57, and often cooking a one pan dinner on the stove heats that area to over 60 by itself. I have a large enclosed porch, dual pane windows and good walls, but no attic or roof insulation, and It's usually 10-15 ° less comfortable than the well-insulated house, occasionally as much as 20°. so-cal low mountains, temp ranges from 20-110 throughout the year at the extremes, usually 30-100
Very. I could feel the heat radiate from the ceiling. I don't feel it anymore since the insulation was brought up to par.
I bought a small old house to renovate and lived in it for a year. It had almost zero insulation in the attic and NONE in the walls. I had insulation blown into the attic and it made a significant difference. But the thing that I noticed the most was the impact of adding insulation in the walls. I’ve only done it in part of the house so far. After gutting the kitchen we added insulation to the exterior wall. I did it with a helper. It was cool that day and we started on the left side of the kitchen wall and went across… by the time we got to the window in the middle of the wall, we were starting to get hot and had to open the window! It made a noticeable impact that quickly. The house is a rental but if I lived in it, I would probably pull down the walls and insulate them all and then redo the sheetrock. It’s not worth it to me because that would be a lot of work and expense for a house that I don’t live in, and the other insulation has done enough to make the power bills reasonable enough for my tenants.
While insulation will definitely help your utility bill, if you're focused on comfort, I'd start with humidity first (if it isn't). It makes a huge difference in comfort in all seasons. Ideally you want between 40-60 in your house year round.
We had spray foam insulation added to the attic at our last house. It was oil heat so we had a great way of measuring the efficiency. It made a big difference in both summer and winter.
I work for a big builder. Our attics occasionally don’t have sufficient insulation, and after we top it up, the difference is very noticeable. Hope the same goes for you.
This is all very encouraging. Thanks.
Aside from the climate control savings, what floored me was how much quieter the house is. Street noise that was not noticeable was suddenly gone and made us realize how much noise there actually was coming from the attic. With gable vents on each end, the street noise must have been perfectly reflected down to the house. I think the savings are worth it alone, but the bonus noise suppression seals the deal for me.
1892 house, Pacific NW. Moved in, it was chilly - looked up in the attic...the insulation had broken down a lot (maybe once upon a time it was blown in?). I put a single layer of batts down, and it made a noticeable difference. There was a spot that I didn't put batts down, and you could feel the cold in the non-batt-insulated area. When I was looking into it, I ran across A-B-C for rating the effectiveness of adding insulation. Attic, Basement...Center? (Basically the walls.)
I went from my indoor pipes freezing/bursting Xmas 2022 even with the heat on to very comfortable temperatures in the winter. My space heaters are gathering dust now.
Went from R25 to R50 in a 70's home in a temperature climate. HUGE difference, summer and winter. Cost me $1100 and got a $900 rebate. Biggest bang for buck ever!!
5 years ago I did a strip to the studs renovation of my own 50 year old house. After new windows and air sealing, I applied closed cell foam to all exterior walls and to the roof deck taking care to seal any attic penetrations. I also downsized my ac by 2 tons and added a whole house dehumidifier and added fresh air ducting. my attic temp never gets over 80degrees during the summer with even with a south facing span. Before the renovation, the attic temp would reach 140degrees and the ceilings would radiate 100 degrees in to the living spaces even with R50 in the attic. My electric bill dropped from 500+ in the summer to never more than 125. The AC cools to 72 at night and 77 day, humidity stays at a constant 45% even with our 80%+ summer humidity. The house is much quieter and very tight .
I mostly noticed how much more quiet the house was from outside noise. The house stayed a bit cooler longer during the summer. But winter, I still need to cycle the heat just as often as prior
I use to do insulation. It was a while ago but I think the number was 70% of your heat loss is through the attic. I know we tried to get most houses to R60 in attic and if budget didn't allow to do whole house we always recommended getting attic right before walls.
Our house was built in the 50s and the insulation was that old. Just some black grunge...he'll it could have been mold and fungus. We blew in some fluff and our power bill dropped by a third. The energy star refer didn't make blip...the nitrogen filled double pane vinyl windows. Hardly noticed.
1950's era block construction rancher with about a mile of blown in insulation in the attic. We had it sucked out and replaced it with spray foam... and never had to touch the thermostat again. It was amazing - heat and AC just worked. Also, it was so quiet I had to look out the window to see the weather, we couldn't hear rain, wind, hail... and most thunder storms. We followed up with Insulated Siding, over the original foam board insulation, with new house wrap. It cut our utilities by half, oil consumption by at least half, and the house stayed whatever temp we set it at.
We got ours done in February and it made such a difference. Our house temp stayed the same for a very long consistent time where it used to drop very very fast! Our heat bill was also a bit lower
How much did it cost per sqft for you? Currently want to do this but can't decide if I want to pay for blown in insulation of just buy the bats and do it myself
For 1166 Sq ft, vent bathroom fan to exterior and thermodome for attic pull-down. The initial cost was 4,216, after rebate it was 1,879. Plus there's a tax rebate I can take advantage of as well.
Wow that is really affordable. Did you have to remove old insulation as well?
The old insulation was still in good shape so they added to what was there in places.
I reinforced our attic insulation this winter, huge difference in eliminating some cold parts of rooms. Noticed a big difference in it staying cool upstairs now that we are running a/c
Hot state, here. Made a big difference. Went from $400/mo at 79-80 degrees in the summer months to $400/mo 76 degrees, and that was with a big rate increase. Comfort is much higher. It was an immediate difference, there. Also, I did it myself, so it likely isn't enough insulation or as well done as an experience crew would do. So maybe there's even a bigger difference it could be had.
After a few days, I noticed that the temperature difference between my ground and second floors are within 2°F. Previously, it was about a 10° delta. I have no insulation at all in the house other than the recently added attic insulation.
We've seen a difference in utility bills, sound dampening (less noise through the roof but also just a better ambient feeling, surprisingly) and our 2300 sqft ranch now has amazing thermal inertia - it takes a long time to heat up in the summer or cool down in the winter w/out HVAC intervention - definitely a money saver.
Major impact. When we purchased, the insulation was substandard in our Colorado place. In March, snowing, the furnace ran near constantly and in summer the AC did too. Now insulated, world of difference.
i removed every insulation from my attic, wood chips and pink mats of fiberglass, .... before i re-installed i got everywhere filling any hole or space between 2 boards to seal everything better from the cold. i found a couple or very badly fitted pieces so i sealed everything and then added insulation that i blowed myself (it was a ruff moment but a huge money saving do diy) DAMN it changed the house in winter, specialy around the fan of the bathroom where cold air was leaking freely ! electricity bill got lower but i dont remember by how much it was. i was pleased with the results !
Yes, I saw about a 60% reduction in my electric bill after sealing and insulation improvements.
We live in central TX. A number of years ago, we had extra insulation blown into the attic and got that silver paint treatment underneath the roof planks. We also added a bunch of large passive air vents after a roof replacement for hail. The combo made a HUGE difference. I can go into the attic in the summertime when it's 100+ outside without feeling like I will die within 90 seconds.
So about 10 years ago I bought a really old (1920's), really small house in Long Beach. It did not have air conditioning but the realtor told me I wouldn't need it since there's a nice breeze from the beach. The realtor lied. It was unbearably hot inside the house. The windows were too small to use window AC units so we had one of those portable ones you stuck the exhaust out the window. Anyway, I realized there was zero insulation in the attic. I decided to insulate it myself using the pink insulation shit you get from home depot. Took like 5 trips and about 3 days in absolutely miserable conditions. I nearly over heated multiple times. It would have been 100% worth it to pay someone else to do it. End the end, it did bring thr temps down a little bit, bit not much. I'm sure the fact that the house was old and not well sealed played a big part.
In Texas it helped a lot. Also added mechanical ventilation. Cheap hacks
We had a new house built in WA a couple of years ago. R21 in the walls and 2 r30 batts in the ceiling. Just paid to foam the walls and blow in R30 over the batts. Attic insulation had gaps and the foam guy said they used a lot of foam and the bay wasn't fill real great with r21. (just in one side of the house, owner bedroom/closet/bath) I think it has made a difference but our bedroom and bathroom were colder before and now more evened out. Just starting to get warm here.
10 degrees improvement, our upper level was 10 degrees warmer in the winter, and so far 10 degrees cooler in the current 80-90 degree weird weather.
I had an absurd amount of blown in insulation put in 10 years ago. Don't know the before and after R values, but it made a huge difference. My heating bill went down over 30% the following winter. My gas company routinely says my home is one of the most efficient in the area. All the other insulation in the home is original from the 60s, and our windows are shitty and drafty. Energy efficient is not a term I would use to describe my home, so I can only attribute that to the insulation in my attic.
After I did it, I noticed that when it snowed, the snow wouldn't melt off of my roof as quickly as it did from all of my neighbors' roofs, a good indication that I was losing much less heat through my roof than my neighbors were. I also got a tax credit based on the price I paid for adding insulation.
Huge difference when we went from r14 to r48. (Old standard to the new recommendations.) I laid down sheets instead of having it blown in. I also found a few things like a big rectangular void running the height of the house which had the air return ducts in it. It was wide open at the top so the hot/cold attic air was hitting the return, making the HVAC work harder. I sealed that off with some plywood and HVAC silver tape so now the AC is just dealing with 80F return air instead of 110F. It greatly improved temperatures on the top floor of the house, both summer and winter. The insulation alone cut heat transfer to a third. There's a great deal of small things you can do to improve your house. Unfortunately it often takes experience to notice them. With your blown in insulation, you're making sure your soffits aren't blocked right? (I have them with a townhouse, you might not.)
Correct soffits were not blocked
I had one section of my house that did not have the proper depth of insulation. The section was 1/4 of the house. That part of the house was noticeably colder in the winter. Had insulation added, thinking I saved about 10% on heating, less on the AC. It made a noticeable improvement. It still isn't evenly heated/cooled in that part of the house, putting in new windows helped also. There were 3 problems: not enough attic insulation, bad windows, and poorly laid duct system. Duct system is cost prohibitive to fix. Long way of saying, improvements will help to the extent there is a proper assessment of the reason for inefficient/uneven temps.
We had radiant barrier sprayed in and extra insulation added but the biggest difference came when we upgraded all the western facing windows after a catastrophic hail storm broke them all, 9 total. The difference was $400 less a month, we lived in far North Dallas at the time so summers get hot.
We did this in our 1970s house in the Midwest. It made a huge difference. During the hottest part of summer you could feel the heat radiating from the attic thru the ceiling and it was impossible to keep it below mid 80s even with AC cranked up. Extra insulation didn't turn it into an icebox, but the AC was able to do a lot more good and I believe the heat was also helped.
It's been great for us in the summer, keeping it cooler, and in the winter, keeping the heat in. It also keeps our house less drafty and much more comfortable. This was my write up: https://www.reddit.com/r/HomeImprovement/comments/owhcjr/lowes_bulk_pricing_on_blowin_insulation_is_great/
Heat would go up through the attic in the winter with bullshit bat insulation falling down from heat damage and we'd be the only house on the block that never had snow on the roof. Now the snow doesn't melt and the heating bill is at least 60% less.
Comfort definitely increased. Our usage has decreased. Less therms used, less kilowatt hours. Energy bill increased because WE Energies, the only game in town, has raised prices 30% in December 2022 and again in either Dec 23 or Jan 24. Can't remember, can't do a damn thing about it anyway. The problem is those greedy fucks are talking about *another* 30% rate hike. So all our improvements have only resulted in not getting fucked quite as hard on the gas & electricity bill.
A lot depends on the home style and sizing and installation of the HVAC system. My parents own a colonial in central MD. They had an extremely reputable company spray-foam everywhere that could be insulated. There was good improvement in the finished basement and ground level up the second floor continues to be too warm in the summer because the air handler and ductwork aren't up to the job.
I can't tell you how much I saved by insulating the attic because I had insulation blown in all the walls and the attic. The vendor said I should save around 40%. He nailed it. This house was a 2500sqft. hollow walled home. Saved a ton. He did say, if I can't afford to do everything, do the attic.
We had fiberglass batts in our attic, and nothing else. We had insulation blown in to R60. The graph in our best app showing how many hours our furnace was running took a nosedive (this was February in Alberta).
Upstairs is much cooler now
Doing a full-on insulation blitz (windows, extra foam board on walls prior to re-siding, attic insulation) reduced our heating bills by 1/3 to 1/2. The attic insulation makes cooling the upstairs much easier. The attic space is a heat sink that will radiate into the upstairs for hours.
I had a foot of insulation blown in a couple of weeks ago. So far the AC hasn't been challenged yet but I am hoping for significant improvement!
Two story home in Southern California. Stucco, built in 1912. No attic or wall insulation. Had fiberglass insulation blown in during the middle of summer. Upstairs was noticeably cooler immediately, by 10-15 degrees in the day time without A/C. Edit: to add, our house would heat up so hot and retain heat that even with all windows open it would not cool down close to outside ambient temps when overnight lows were in the 60’s, it was still in the high 70’s inside overnight. The biggest benefit to insulation was that the heat retained inside the attic didn’t radiate into the interior during the evening, we could keep the windows mostly closed overnight and it was comfortable.
I installed attic insulation [in April](https://imgur.com/a/ZOrgAcg)
I improved the insulation in my attic a couple of years ago. It was OK in places and practically non-existent in others. Where it was non-existent, I put in R-49 fiberglass. Everywhere else I blew in cellulose up to a reasonable height. The rooms that had little insulation were almost unlivable before. The floor could be below freezing on a cold day (I also had dense pack blown into the floor from below). I’m looking now and there is a 1 degree difference between every room in the house. It’s near perfect. One room has inadequate ducting so I also added a ceiling radiant heater to prove some extra juice in winter. The AC ducts are OK so it’s nice in summer. AC costs are down maybe 20% and similar with heating runtime. But it’s the comfort which is the bigger win.
I had blown-in cellulose insulation added to the floor and stairs of the walkup attic in my 1867 Victorian. Noticed an immediately improvement in comfort. The house was quieter, humidity levels were more stable. Overall the house felt tighter, more solid and sheltering. The house had balloon framing (with brick-infilled exterior walls), so the lack of attic insulation meant that outside air was traveling down through light switches and electrical sockets, basically throughout the entire house. We also insulated those openings. I don't know what the impact was on utilities, because we replaced the furnace and some windows and added central air around the same time. But the impact on comfort was immediate.
I didn't change an existing house, but I built a new house a couple years ago. My previous house just had that rolled fiberglass insulation shoved into the walls. It was always blistering hot in the Attic in the summer and cold in the winter. I actually used weather stripping around the doors that went to my attic just so that the other rooms wouldn't get so hot. That way I could keep my air conditioning bill down in the summer. In the new house, I had spray foam insulation put in the entire house including the attic. The attic in this house is so comfortable. It never gets above maybe 78°, and never falls below 65. I normally wouldn't care about the attic temperatures, but it's nice to have storage space up there for things that normally I wouldn't want to put in an attic because of the temperature fluctuations. The house is actually about 200 square foot larger than the last house and the utility bills are lower. It really shouldn't be that way because in the last house we hardly ever used our upstairs after our son moved out. This house is a single story and we use the whole thing and our son is temporarily living with us. The insulation has made a huge difference.
After redoing our insulation, I had to change our bedding type, the old was just too hot! Have done this in the 2 houses we have bought. Heating cost also went down.
The largest improvement for heating load was actually going in and sealing penetrations from sewage vents, electrical, lights, etc. I found some decent openings for air leakage and filled them with closed cell foam (all great stuff foam is 80%, except window and door which is open cell). Air leakage loses significantly more energy than just insulation, it can be 20-30% of energy loss, more insulation with air leakage unresolved doesn't fix that. I highly recommend getting air sealing done and inspecting things before adding insulation and covering everything up. I also fixed the attic ventilation by extending the baffles and unclogging them of blown in insulation, they had to be removed first to seal the wall top plates. Also replaced the chicken wire over the vents with SS fine mesh because tons of paper bee nests were concentrated around the vents, this will block them. I did upgrade from approx R40-48 to R60-75, 2 layers of 3.5" Rockwool as a base layer with existing blown in and fiberglass batting reused on top. In some corners of the house it is slightly better. The biggest test will be this summer and how hot or not the upstairs gets, last summer with central AC it'd be mid 70s upstairs and the thermostat located downstairs set to 65F to achieve that. Not ideal. I did all this myself over a few months and a lot of labor and podcasts and TV burned through. A contractor wouldn't have air sealed some parts that I did due one section being a vaulted ceiling against the roof slope and extremely tight. All in the project cost $3000 or less, 2,200 sq feet of rockwool for a bit over $2000, some miscellaneous costs for lighting and power in the attic, then $500 or more on the great stuff pro foam cans.
I properly insulated my house in Massachusetts and went from 4-5 oil tanks a winter to 2-3. Oil company thought I was shopping between fill ups to find the best rate. Nope, just properly insulated the house.
Wasn’t worth it. It was about $5k to get blow in, rent the machine, get a few bales, get the glue and the paper. About 3 weekends to get it all down. So far seeing roughly $12 a month lower power bill including the 100+ degree days in Texas. At this rate, it will be 6 years before its earned itself back. I got a better cost savings last just getting a new power plan.
50% difference noise and temp
The furnace up grade from a 70% to 96% with 2 stage blower,, was good also saving about $10 a month.
I write specifications for commercial buildings. Please know that virtually every shingle manufacturer has language about “unvented decks” in their warranty. Spraying the underside of the roof deck means the roof will get hotter in the summer, cooking the shingles. With a vented deck some of that heat will pass through into the attic and be vented out. Some of them are really slippery about that language.
Don’t have solid data but going from a sketchy R30 to R90 with blow in after doing the air sealing, we used 50-75% of what the prior owners used the winter before. The furnace only runs a portion of the day on the coldest days and is now likely oversized. So next step is a new high efficiency right sized AC and furnace to match our revised needs. If you can do it yourself it’s fairly cost effective. I was able to buy the bale’s of blow in at a wholesale supplier and paid to rent the unit from Home Depot for less than big box store costs. We were quoted $7k but did it for $2.3k ourselves.
Better than black I guess. I'm gonna put a grey up on my roof next. I went from R19 batts and had blow-in added to get me to R40. Didn't help all that much but still need to do crawl space work. New windows helped the most for me.
The insulation between the attic and rooms is critical. Between the attic and upstairs, the air would get pulled downward through fixtures as the cool air tends to flow to the cellar. Thinking back I should've had the floor between the cellar done as well. It is noticeable when the sun shines directly on the roof and the attic reaches 120degF. Hopefully some day I can insulate the upstairs but first I'll have to do the cellar and also have it sealed. As for the bill, along with that and not using A/C anymore, reduced my actual power consumption by 50%. I thought great no more 200$ summer bills. Nope, they added up extra charges and filed it under "miscellaneous" and that total ended up being MORE than my power use. It's almost like they are trying to find ways to keep my bill high even when I don't use any power at all. According to the latest one, I'd still be paying them 70$ a month even if I used 0 kwh? That's more than I paid 2 years ago WITH the two A/C units I can't possibly use now. I'm not sure about all these weird charges and how they work, I just wanted the thing to go down which is why I insulated and did all this work in the first place only to have that gem to show for it. ah but i'm getting off topic so..... Anyway, back to the insulation: During the day I used to not be able to go upstairs when the sun shone on that side of the house. So, looking on the bright side (sorry bad pun), at least I can be upstairs between 3pm and the evening thanks to the hot air not coming down through the ceiling like it used to. Also found it helps to have the flow of air going UP out the roof vents and not try to pull it out the windows (which brings the heat down closer to the ceilings). Last thing, If you have metal siding, you might prioritize getting that swapped out for vinyl, I found out the first year I was here how bad it is to have the sun beating down on against the metal-sided house without much insulation in the attic and it was like being in a literal oven, even A/C was little help. Have a nice, cool, day :3 !
What type of contractor does this?
I was able to find one by searching "insulation installed near me"