New Home Heating Ideas

[dave1949]

If it appeals to you, passive solar with earth berms is about the cheapest heat you wll ever get. We are in our 6th year of living in our passive solar home with earth berms on three sides and have no regrets. We haven't used any heating so far this Fall and have had days in the 50's and hard frosts over night, even 24* a few mornings back. We usually start using our masonry fireplace sometime in November and burn less than one cord per year.

Under lessons learned, I would emphasize attic insulation, air exchangers, and don't under-estimate the possible need for AC for temperature and humidity control in the summer. The north bermed wall can be cool enough for condensation to form on its interior surface (down near the floor especially) in hot, humid weather; that cannot be allowed-- to avoid mildew and mold. So, you either circulate lots of air or dehumidify with AC. Also, thermal mass works in both directions, its temperature will slowly climb in prolonged hot weather and it does a good job of retaining/storing that heat, just like in winter. You may end up surrounded by 78* concrete even in "cool" summer areas like Maine.

 

[Carl_NH]

Hmmm, yeah I just threw the number R-19 out there without really thinking - haven't gotten to the details of planning yet. I guess I was assuming that this was the max you could get in batts for a 2x6 wall. I see now that the high density is R-21, a little better. And spray foam can attain just R-20....? How does one significantly improve on this?

Use 1-2" of spray foam to seal the envelope and then 3.5" traditional fiberglas. The spray foam is around R7 per inch I think so with R7 + 3.5" R15 is R21 BUT the big difference is blocking the air infiltration with the first 1".

The combo of spray foam to the entire shell and balance with traditional insulation is most cost effective.

Carl

 

[Redneck in training]

I'd also encourage you to maximize sealing, insulation and solar gain. Beyond that, any of the options that have been mentioned can work.
I just converted from oil heat/hot water to geothermal. Total cost will be about $20K. Of course, my oil bill will disappear, but I don't know yet how much my electric bill will go up. I'm expecting about a 10-year payback time on the $20K cost, but this is because we have always kept our house really cool (12C when we're not at home or in bed and 16C the rest of the time). Somebody with a saner/more comfortable household temperature regimen could have as little as 7 year payback on geothermal. ie, YMMV!
BOB

You can easily calculate the power consumption for geo from your oil consumption. 1 gal of oil is 138700 BTU=40.64 kWh. Since geo doesn't make heat but transforms (pumps) large amount of low intensity heat into smaller amount of high intensity heat the perceived efficiency for floor heating is about 3.8-4.
In other words 1 gal of oil will be replaced by about 10 kWh of electric power used by geo times efficiency of the oil boiler.

 

[Dr Dave]

Hmmm, yeah I just threw the number R-19 out there without really thinking - haven't gotten to the details of planning yet. I guess I was assuming that this was the max you could get in batts for a 2x6 wall. I see now that the high density is R-21, a little better. And spray foam can attain just R-20....? How does one significantly improve on this?

Go with the high density R-21 add high density foam panels to the exterior, this isolates heat transfer to 2x6 studs. I used 2" R10 on my exterior before residing, only had R-13 in 2x4 walls. Also replaced windows, this cut my propane use in half. I used 1 1/2" on my parents old farm house, it was much quicker to use standard lumber to frame out door and window openings, then installed an electric air to air heat pump, the sure are happy with the low utility bills.

Dave

 

[dclynch]

My nephew had Geo thermal installed in Mid Michigan last year up front costs were expensive I think 17,000 but the guy that installed it gave a 1,000 off for cash I then belive he got a 5-6,000 back from the government for using alternative energy so he ended up spending about 12,000 out of pocket. He figures it will pay for it self in 5 years as his old boiler ran on propane. I have made my mind up that when my furnace finally takes a crap I am installing Geo thermal. We have a very small house that is insulated well and my propane bill is anywhere from 1,800 -2,400 a year. So if it cots me 12-15000 to have it installed it will pay for itself in 6 - 7 years I dont think there is any other system that can beat the return on investment if propane or electric is your only options for heat and AC

 

[Zick]

Use 1-2" of spray foam to seal the envelope and then 3.5" traditional fiberglas. The spray foam is around R7 per inch I think so with R7 + 3.5" R15 is R21 BUT the big difference is blocking the air infiltration with the first 1".

The combo of spray foam to the entire shell and balance with traditional insulation is most cost effective.

Carl

This is exactly what we did w/ our 2x6 walls. Sprayed in 1-1/2" of closed cell foam and then put in R-13 batts on top of it.

 

[Carl_NH]

This is exactly what we did w/ our 2x6 walls. Sprayed in 1-1/2" of closed cell foam and then put in R-13 batts on top of it.

What was your estimated cost per SF or as a total for your house and SF coverage?

 

[Zick]

What was your estimated cost per SF or as a total for your house and SF coverage?

Unfortunately I couldn't tell you because the cost for it wasn't broke down in our overall total cost for the entire house.

 

[204saskman]

I currently heat our house with 2 grain/pellet stoves. Mine will burn anything under the sun. Before the price of grain went up i was heating my house for next to nothing. I was burning screenings and i was burning about a buck a day fo the 2 stoves. Now im up to about 2-3 depending on the weather. I was burning wood pellets with good stable heat but the cost was to much. multi fuel stoves are the answer if you are going thios route. I like mine alot and find them to be very efficent and i enjoy the heat.

 

[Dr Dave]

What was your estimated cost per SF or as a total for your house and SF coverage?

I got quotes from $1.25to $1.50 per sq/ft per inch for spray foam:shocked:

Dave