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Old 07-30-10, 08:39 PM   #268
AC_Hacker
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Default Get a Small Air Conditioner or De-Humidifier and Let's Go...

Quote:
Originally Posted by Greebe View Post
I am planning on putting together a system for my 650 sqf shop so that I don't have to run a wood stove all the time. If it goes well I want to then look at doing the same thing for the house.

I was planning on doing a ground water version so as to save some time and money.

What I am really interested in is your homemade heat pump. I didn't see where you go to on this post, but there was a link that showed one of your completed models.

If you have any more info on your pump, I would love to see it. That is the only thing that is keeping me from trying to do the groundwater heat pump system, is the pump.
Hello Greebe, welcome to Ecorenovator...

A 650 square foot shop, huh? Sounds just great.

Don't know if you read the whole thread from the beginning, but what motivated me in the first place was that I wanted to try to come up with the most efficient heating I could for my small home. My home is not much bigger than your shop, and I don't heat the whole thing, plus the winters here in Western Oregon are pretty mild compared to much of North America and many parts of the world.

After much study, I concluded that it is more important to reduce the amount of heat energy you require, rather than to try to generate more.

This lead me to realize that I needed to make very large improvements in my insulation, which has come a long way, and is still in progress. I am removing the lath & plaster, thickening the walls an additional 2 inches, and layering in rigid foam board to fill the wall cavities. I have since learned that there are easier, cheaper, more environmental ways to proceed in insulating, but my work is paying off nonetheless.

After talking to an old-timer, I have come to realize that I don't need to heat the entire house. It was seen as absurdly wasteful as far back as the early 1700's and it is still absurdly wasteful today.

Solar home heating is tough where I live, as it is so overcast most of the winter.

So, considering all of the above, the most efficient heating system I could find is Ground Source Heat Pump with Radiant Floor Heating. Very expensive to put in, very cheap to run.

I say all this, because my heating requirements are low. In fact, they are so low that there is no commercially produced Ground Source Heat Pump that is correctly sized (small enough) for my needs. Ground Source Heat Pumps for warm forced air can be found on Ebay in the neighborhood of 1.5 Tons, more capacity than I need, but not unreasonable. Water-in water-out, on the other hand tends to start in at around 4 Tons (and about 4 Tons of cash).

Since I don't have so much money, I thought I'd try a DIY.

I started out building the heat pump from a used dehumidifier. I started there because I thought it would be the most difficult part. It really wasn't so difficult actually.

The ground loop was the most difficult. It just about did me in.

My advice to you would be to start with radical insulation (about 2x greater than your local codes require), then use electric heaters and Kill-a-Watt meters to find out how much heat you really need, then contact some well drillers and/or some GSHP installers near you, to find out how much loop field you're going to need to create that heat. You should also investigate high efficiency ASHP, as they are getting pretty good.

After you know how much loop field, then it is time to build your Heat Pump.

* * *

But, hey... if you want to start with the heat pump, I can walk you through it, right here.

If you (or anyone else for that matter) want to do it as an experiment, go get a small Air Conditioner or De-Humidifier.

Let me know when you have your unit, and we'll get started...

-AC_Hacker

Last edited by AC_Hacker; 08-07-10 at 11:02 AM..
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