Hi i have been looking into geothermal for a long time but have yet to pull the trigger.

I have a 3300sq.ft home with another 1500sq.ft of basement under it, i also heat a 1400sq.ft shop to 10c /50f.  The house also has alot of open areas... so the over all envelope is big for only 3300sq.ft


the shop is heated with a 12KW boiler and the house has two 25kw forced air.  I burn 4500kwh a month and it costs 6.6 cents a kwh up here.  I have gas in the house but it is only for the fire places and cooking range.  Worst month is about 10,000kw.

The house is 6 years old and is 2x6 with 1.5" if SM on the out side, lots of windows but they are triple pane with low E



I have had quotes for 70K to do the house and shop, that would also add heated floors in some areas (i would like a more even heat)  Im pretty handy and whould beable to install the system myself.

What would setup would you use for a home/shop like this?   Is there a industrial unit that i could use for everything.. ie put heat exchangers in the furnaces and run hot water to them as well as the house and shop floors?  or would it be better to do a bunch of smaller units with water to water and water to air?

Thanks

It is difficult to say what we would do in your situation without seeing the property. But seeing your description does raise some ideas. There are single geo units that provide water to air and water to water. This will provide 100% DHW, radiant heat capability, and hot air/AC. Just my opinion but when you get over 70-90KBtus or you have a very spread out area it may be cost/energy efficient to use multiple units. I'm sure others here have more ideas. Have you done a blower door test to find the leaks and heat loss?

i have never done that test, i know my front door leaks.. other than that the house is pretty tight, its cold up here in winnipeg. so my bills are not that bad seeing as how many sq.ft im heating.

payback is the main thing for me and if if it were to cut my bills in half it would save me at most 200$ a month... so if i could install the system for as low as 30K (i think that would be hard to do) the payback would be 12.5 years.. thats not so great.

here is what i have used in the last two years..

Is it reasonable to infer from your tables that the house base load (no heating or cooling) is only about 800 kwh / month?

If so, and I'm correct in assuming you have straight electric heat, a properly executed geo system should save 2/3 of all kwh in excess of 800 per month.

That assumes a COP of 3.0 and same steady thermostat setpoints before and after.

If you are now using heavy setbacks (reducing setpoint for sleeping or times away from home, they will not be as cost effective with geo)

Yeah i might burn 800kwh with out any heat or cooling. The house and shop is 100% electric heat.

The house is 68f when we are up but 64f when we are sleeping. but the shop is set at 50f all the time

So looking at it best case it will pay me back 2400$ a year... humm if i can get it installed cheap enough it might be worth my while.