Air sealing/Insulation ROI

[Devonian]

For those who have upgraded their attic insulation and air sealed the house what kind of energy savings did you see? I had a contractor air seal the attic and basement and blow in 12 additional inches of insulation last month. I’m hoping burn less wood and oil this winter.

For reference, last winter I burned around 3.5 cords and 600 gallons of oil plus whatever I spent on running the heat pump.

 

[peakbagger]

I saw roughly a 25% reduction. The big payback is the air sealing

 

[Devonian]

Thanks. That would be great if we saw the same reduction. Do you recall what your blower door number were? We went from 4500 to 2800 in a 3,000 sqft ranch.

 

[peakbagger]

Sorry it was quite a few years ago. I know that they had to install a fan with a timer on my bathroom to get the air changes up over the minimum. I had a fairly tight home but there were problem areas, the big one was the box over the sills and the sills. I also had some can lights up in the ceilings that leaked a lot. Generally the big payback is infiltration which is what the blower door test is for. It does not care what type of insulation you have or if you have insulation. I did get them to spray a new ceiling I installed in an unfinished room but how they justified it was that it was air sealing not insulation. Out utility rebates half of the cost up to $4,000 but limits the work to some unknown years to payback. I dont think the contractor got up to 8K but tried hard to do so.

The bummer was it was done while it was cold (-10 F) out and some of the foam pulled away from the rafters. I complained to the utility and the contractor did some spot repairs but 10 years later I really need to go back and respray a lot of areas where the foam shrank. The areas inside the envelope was fine but the ones up against cold roof sheathing were less successful.

 

[Devonian]

Thanks for the responses. We got a heafty rebate from our utility company as well.
I’m looking forward to seeing how much improved the house is this year. We had a very hard time getting warm air from the wood stove back into the bedrooms. It would be great if the tighter house makes it possible to heat more area with the stove.

 

[Dobish]

i just had my cousin (getting a PHD in sciency house building stuff) do an energy study on our house, and he confirmed that we are in fact loosing quite a bit of our heat to infiltration and improper air sealing. Not that we really needed him to come in to tell us that. We haven't done a blower door test, since the last time we were going to do one, there was no insulation in the house, and no drywall on half of the house!

That will be next summers project I think.

 

[georgepds]

I've been sealing up the holes in the house.. The most notable thing is it's more comfortable...

Wood use went down by half when I replaced th smoke dragon with a Woodstock progress hybrid.. can't say there was any effect on use by the sealing

 

[EatenByLimestone]

Snow melt was the first clue to me that I had heat escaping from my newly finished off attic. It horrified me. I poured all that money into it and had snow melting all over it.

I ended up opening up an internal wall and foaming across it to stop heat from moving up. I sealed kneewall crawl spaces with foam boards, then foamed and taped the edges. Then I went through and took care of any other spots I could find where air could escape around beams, fixture boxes, and windows with caulk.

Although I have energy used records, I don't have hard money saved data since year to year weather is different. I can tell you that snow lasts a lot longer indicating a lot less heat escapes.

I can also tell you that if I knew then, what I know now I'd have had closed cell foam sprayed and would have avoided the cellulose and fiberglass insulation I used.

 

[Woody5506]

Also in the beginning stages of having air sealing and blown in cellulose done in my attics. It's a split level so I have 3 attics to do. 1 of which will be put off until the ceilings are dry walled some day...

Really tinkered with the idea of a 2nd wood stove but settled on beefing up insulation first. And really, the attics need it. Some areas have none, and others have 3" at best of crappy old fiberglass bats. I'm kinda interested to see the cost of spray foaming it all, but for 3 attics the number I have in my head would be over 10K...Based on an estimate I had for a whole upstairs bedroom at my old house which was 4k. Really can't wing that much money for insulation now, and quite honestly I would rather put a second stove in + blow in insulation for about the same cost as spray foam. The guarantee with a second stove is that it's certain to keep things warm in that part of the house, and I'd never have to turn my furnace on anyway unless I wasn't home.

 

[EatenByLimestone]

You don't have to do all the insulation at once.

Do 1 attic at a time. A new stove, hearth, chimney, etc will run 3-4k. An attic would run the same and work summer and winter.

 

[EatenByLimestone]

The problem is insulation isn't as sexy as a stove.

Stoves need care. We can lovingly caress them in summer with a damp cloth to keep the dust off, and use them as an excuse to play with fire in the winter.

If you go up in the attic and fondle insulation you're just weird.

 

[EatenByLimestone]

However, a really low utility bill is fun to flash around. While your neighbors are spinning their meters running the a.c., you can shrug and say, "Meh, the a.c. doesn't run that much."

 

[georgepds]

"However, a really low utility bill is fun to flash around. "

Current credit on the electric bill is~$2700.. I may have overdone it with solar and efficiency.

I'll have to take up coin mining this winter to eat through the credit. At the very least the servers will heat the house

 

[Woody5506]

The problem is insulation isn't as sexy as a stove.

Stoves need care. We can lovingly caress them in summer with a damp cloth to keep the dust off, and use them as an excuse to play with fire in the winter.

If you go up in the attic and fondle insulation you're just weird.

You're absolutely right, and what I'm trying to steer away from as far as buying the more pleasing option vs the more logical option (insulation).

 

[Devonian]

We’ve been fireing up the stove and more heat is making its way back to the bedrooms compared to last year. It’s still a struggle for the stove to heat the far reaches of the house but it seems like an improvement. Still waiting for it to get really cold for a good test.