Insulation project thanks to $700 electric bill


Old 02-20-09, 11:22 AM
Thread Starter
Join Date: Jan 2009
Location: Central Indiana
Posts: 1
Insulation project thanks to $700 electric bill

Good afternoon everyone. This is my first post here but i have been reading for a while now. Let me give you a little history of my money pit...
We moved into our house in December of 2007. We had 3 $500 plus electric bills for the first three months we were there. After consulting a number of different sources we decided to replace our 30 year old forced air electric furnace with a new air to air heat pump. We were convinced that this would reduce our bills significantly. We also made plans to replace our old windows and replace the worn out cedar siding on the house as well.
When we received our November bill of $540 we went into panic mode. December was $600 and January topped $700.
Our windows were replaced with new Krypton filled heat mirror lined windows last week. We have a contractor replacing the worn out and crumbling cedar siding with new fiber cement siding. We have him also adding a 1/4 in fanfold and taping the seams.
We have an insulation contractor coming in to fill the first floor walls with low expansion foam and i am going to try my hand at expanding spray foam on the bandbox in the crawlspaces of the house.
The good news is that this should help significantly next year. The bad news is that this was not able to be completed until now. I thought this would be a good place to track our progress.
Any thoughts or comments on this would be appreciated.
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Old 02-20-09, 01:02 PM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,399
It's more than a little late now but you should have done a complete energy audit before installing anything. This would have included thermal imaging to determine the amount and effectiveness of any ceiling and wall insulation and a blower door test to determine the rate of air infiltration the locations of the infiltration. Then you would have known where the most bang for your bucks was to be had.

At the same time you should have done (or had done) a comprehensive heat loss calculation, also know as a "Manual J" calculation. From this you can further define what improvements in the building envelope will do for your bottom line savings. It is also required to properly size your heating system.

Did your heat pump installer test the existing ductwork for leakage? He should have and then sealed the leaks with a minimum of foil tape or better, with duct mastic. So-called cloth duct tape is a wonderful invention but it is really lousy on ductwork because first, it doesn't seal all that well and second, it dries out, crumbles and then you are as bad off as if it had never been applied. Your installer should also have ascertained if your existing ductwork was adequate for the heat pump as ductwork is often minimally sized and the heat pump operates at lower discharge air temperatures than does an electric furnace.

Did you get a new thermostat with the heat pump? Does it have an outdoor temperature readout? Does it have the ability to "lock out" the emergency electric heaters above a certain outdoors temperature? It should. Do you use a "night setback" on your thermostat? Generally speaking heat pumps should be set at one temperature and then left alone. When night setback is used it often causes the electric emergency (or back up) heaters to be energized when the thermostat is raised for the occupied times. This will often totally negate any potential savings from the heat pump.

I don't know about your area but where I live taping of the seams on an insulation installed on the outside of a house would be an absolute no-no as it creates a vapor retarder on the wrong side of the wall. This will allow water vapor (moisture) from inside your home to move into the wall cavities where it will condense. This condensation can be detrimental to the wall cavity insulation and also the wooden structure. It can also promote the growth of mold.
Old 02-22-09, 01:26 AM
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Join Date: Feb 2006
Location: Williamsport
Posts: 713
Furd has a lot of excellent points that I just also learned about. I would not of replaced your heating unit until all the other stuff was done like your insulating, your new siding, windows, etc. I have an old furnace that I want to replace, but I am waiting until I get new windows and siding. I have insulated the whole house since we moved here 3.5 yrs ago and have seen a big difference. Our first yr here (2005) we spent about 4500 dollars just in heating oil between Oct 05 til April 05. That was at low prices. Then in the winter of 07-08 we spent 3300 and that was with a huge price increase so the savings for just insulating the attic and walls have saved me a lot!
We also have been putting plastic on all the windows and the amount of air coming through them are astounding. Just last week we had wind gusts of up to 30mph and plastic actually popped off 2 windows b/c of the wind.

Good Luck with all your projects and welcome to the forums!
Old 02-22-09, 05:12 AM
Join Date: Oct 2008
Location: New England
Posts: 9,999
Greetings ontuy and welcome to the board. It sounds like you are well on your way to reducing those heating bills. In your defense, since I can feel a bit of heat here, the steps you have taken are exactly what the construction industry recommends and it’s a shame. Talk to a heating guy and you will get a new heating system, windows, insulation, or siding, and they all will reduce your heating costs by some miraculous percentage. The bottom line is you are getting there and I hope you stay with the board as there are some more steps you can take to improve your home.

You say “the first floor walls with low expansion foam” is this a two story and if so, what is in the walls upstairs? You’re adding DIY spray foam in the crawl space, no personal experience, but from following the related posts on this board, one problem is the current temperatures, MUCH better when it is warm. Also be well prepared when you start so you can go start to finish. Be sure to seal the wood to foundation in the process and definitely come back and tell us how you made out.

Now, before you start on the crawl space, you should decide what you want to do with the walls and floor. Heat loss through basements and crawl spaces is a large part of your expense. Describe your crawl space and what is down there, dirt floor? Pipes? Ducts? And so on.

On the technical side, as furd mentioned, you don’t want to have two vapor barriers. Where the fan-fold is applied over a wall that is being filled with foam, there is probably no problem. If you were to put the fan-fold on a wall with fiberglass or nothing, then it could act as a vapor barrier in the wrong place. Check it’s permeability, it may only be a vapor retarder which wouldn’t be as bad.

Let us know,
Old 02-22-09, 10:21 AM
Join Date: Nov 2002
Location: USA
Posts: 118
furd has very wise advice

I remember years ago listening to the "Click & Clack" auto advice show on NPR, and they were gently ridiculing a diy caller who had done this and that to fix his car. They said finally "maybe you should find the problem before you fix the car," and then proceeded to give advice on what the real problem was. The average homeowner like me who has barely passable diy capability finally learns to do research on home energy and insulation problems. Even getting an energy audit with thermographs where the audit contractor will spend sufficient time to explain everything is hard. Maybe part of this problem is how well qualified contractors really are. Even in the case where I know what some of the major problems are, it is hard to get an insulation contractor who can propose a good solution. This must be a big problem in this economy where homeowners are trying to upgrade a house.

It would be nice to have an "energy consultant" who is the home owner's rep, and the "energy consultant" knows the subcontractors who can handle the project, and this "energy consultant" is honest and a real pro. I think the fee would be worth it. Whether such people exist or not is an unsolved problem.

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