Hi everyone

[Blauhung]

been lurking for a while and figured I would say hi.

Wandered over a while ago when I was linked here by some people on XtremeSystems.org who saw AC_hacker's work on geothermal and were using mini versions of geothermal loops to cool large'ish farms of dedicated computers for distributed computing. I was thinking of doing similar, but started reading further into it and rather then spend money to cool my computers, why not reinvest that money into reducing costs of heating/cooling my house.

I live in the burbs just west of Portland, OR and am a Chemical Engineer by occupation and am excited to put some of my knowledge to use (which my job doesn't quite flex as much as I would like).

so yeah, Hi

[Daox]

Welcome to the site. A bank of computers, interesting application, but a good one.

[AC_Hacker]

Originally Posted by Blauhung

...who saw AC_hacker's work on geothermal and were using mini versions of geothermal loops to cool large'ish farms of dedicated computers for distributed computing. I was thinking of doing similar, but started reading further into it and rather then spend money to cool my computers, why not reinvest that money into reducing costs of heating/cooling my house...

Blauhung,

I'd like to extend a personal welcome, both as a fellow traveler from Xtreme Systems to EcoRenovator, and also as a fellow resident of PDX, our fair city.

I learned a lot from the folks at Xtreme Systems, and I owe them a huge Thank You... and I've learned a heap since then, focusing on domestic heating, and insulating.

If we can help you in any way to get started, don't hesitate to ask.

And since we all learn from each other, please know that we welcome photos & descriptions of your project(s).

Best Regards,

-AC_Hacker

[Blauhung]

Thanks guys, really at this point I'm just planning things out for projects to work on in the house. So far the wife and I have been working on mostly cosmetic stuff but on some level this doesn't appeal to me all that much as it doesn't really tax my abilities. My motivation may change shortly as in 5 weeks we're due a baby girl, but I'm excited about the possibilities.

Within the realm of computers I've done lots of work around placing them in odd locations and cooling them by odd means. Started out with running all my TV's using only a computer and the internet and dumping cable. Then caught the bug that a computer system offers much more possibilities for entertainment on the road then an average CD/AM/FM system, so I gutted that out of my car and now have a small form factor computer with all of my music/audio books/GPS/Engine monitoring/backup camera... and other assorted features run through a touch screen I hacked into the dash.

going to take up a few posts here to boost myself up over 5 while i lay out my plans.

[Blauhung]

Now that I'm a home owner and starting to get over the first few years of debt issues, the wife and I can start on fun projects. SOOOO, my current outline of what i would like to do is very similar to AC_hackers project of doing radiant floor heating with the hot supplied by a ground source heat pump. I'll leave it here for now untill i can work my way through the last of your thread to make sure I'm not presenting too much information that may have already been stated



1. Drill or excavate pipe into the back yard
right now looks like mostly its a cost analysis of what is cheaper
a) renting a backhoe for a day or so and dropping in pipe (and dealing with the wife yelling at me to fix the dead grassless patch in the back yard)
b) sourcing some home made drilling equipment (and dealing with the wife yelling at me to fill in the death traps)
-drilling sounds more fun just on the principal of sourcing all the stuff I need and problem solving, and costs for transporting a backhoe to the house are kinda high, so drilling might end up cheaper. So option b will probably take longer, but might be cheaper and more fun, leaning that way

[Blauhung]

2. sourcing and sizing heat pump components
Found a very nice source for a Pressure vs. Enthalpy diagram for our favorate DIY refrigeration gas propane at
www.chemicalogic.com/mollier/default.htm
I can do a quick pictorial lesson later on how to read and use the diagram to see what's going on inside your refrigeration loop and how it can be used to size a system. basically from that you can use your desired temperatures, heating/cooling load to setup an envelope on what your compressor needs to cope with and what pressure drop needs to be achieved by your metering device (cap tube, TXV, ect...)

[Blauhung]

3. Radiant heating
This one seems to be the most straight forward of the list of things. We live in a split level home, the garage and office are on ground level with the bedrooms directly overhead with the living room and kitchen being off to the side halfway between in elevation. The living room and kitchen by far make up the largest portion of the house and this is also the section with the most exterior facing walls/ceiling/floor, so this will be an easy first target for insulation and heating. We currently have a 20 year old forced air natural gas heater that was high efficiency in the 90’s so probably not so much by today’s standards (haven’t really checked). I just installed laminate flooring in there and it now looks beautiful, but that also means pulling it up and putting in radiant heating less appealing to the wife... but it does have crawlspace under it with a good 5’ of working room so it would be very very easy to just pull out the in place insulation, run PEX through the joists and drill it to the subfloor with Al heat spreading plates. We are also planning on replacing carpet in the bedrooms, so this would give me the perfect time to go through room by room and put in loops above the subfloor with some form of the slab up there, but that would be for later. I know that these require higher temperature in the loops but that brings me to my next point.

[Blauhung]

4. Water pre-heater
A few years ago our water heater started dripping... so I started shopping around for alternatives. Then the drip turned into 5 gallons a day, which turned into 5 gallons an hour, so on and so forth, so we were rushed, but I think I picked out a very nice tankless on demand natural gas water heater. Due to the rush to get hot water, we had to have it installed rather than me trying to finish up my research and we were presented with the question of indoor or outdoor when the guy came in to do the install which I wish I would have gone the other way. Because of the higher rate of heat transfer when a tankless is in use, it requires larger gas pipe and larger exhaust ventilation, and the existing heater in the garage had too small of both. So the problem was either route a larger gas line off the main across the garage and drill a hole for the vent, we could do an outdoor model and just route the hot and cold water lines across the garage the other way (the outdoor was $500 cheaper as we were quoted). So now our water takes over a minute to get hot due to the extra line, and we have to worry about the cold line freezing in the winter if it does drop below 32°F. But of course the units aren’t interchangeable... oh well back on topic

With a heat pump, and a large thermal mass of the floors, I could pre-heat water up to 100°F’ish in the GSHP, then run that through the tankless to get up to full temp for hot water needs and extra heat for the floors. This would also serve to drastically lower my gas bill for heating water as well as my home.

[Blauhung]

5. Doing heating and cooling
So my wife doesn’t like hot weather, who knows how she lasted living in Arizona for 4 years, but she gets very grumpy. So the needed output of this project is of course heating as the house would be relatively unlivable without heat, but my life would be made much more comfortable for the month where it’s hot outside if I could cool the house as well. So I want to look at options for both heating and cooling. From the looks of things forced air cooling is still the best way to go as any form of radiant cooling would require a large enough thermal mass that the temperature could be maintained above dew point and still exchange a reasonable amount of heat. The only ways that seem to accomplish this is a concrete slab in either the ceiling, or in the floor with good air circulation. Portland is still rather humid in the summer and the dew point tends to stay near the actual temperature. So forced air cooling it is and that’s not too hard as we can use the existing ducting, and GTHP’s are at their most efficient when cooling. So I have the option of either trying to have a separate valved off loop on the compressor that flips from a water->water config, to an air->water config, or just have a separate heatpump. Leaning towards 2 separate heat pumps
PRO’s
-less complicated
-can size all the components for different loads
-could run water pre-heater at same time as cooling, and to some extent, pre-heater would pull heat back out of geothermal loop at the same time as it’s being added by the cooling unit which would result in some slight efficiency boosts when both were running
CON’s
-not as neat
-need to buy another compressor (though might be less than the extra valves)

[Blauhung]

and there now I have a good stretch of posts and put up pictures and whatnot, now to finish off the rest of AC's thread before i try and get in on the discussion over there.