The Homemade Heat Pump Manifesto

[randen]

The GSHP has been operating 24/7 for about 3 weeks. With the outside air temps around -5 Deg C up to 2 Deg C. during the day and no sun the shop temps stayed at 19 deg C. I had to watch the evaporator for icing up as its on the ragged edge with no anti-freeze and the loop temp at 6 Deg C. The high side was sitting at 250psi and the temp out from the condensor was 28 Deg C. Today I had some time to experiment. I had seen that the ground loop temp had actually risen to 8 Deg C so I increase the pressure to 290 psi HS and the condensor out was 38 Deg C. and the evaporator showed no sign of freezing up. The shop temp popped up to 26 Deg.C. What a difference the extra 2 Deg.s in the loop temp. makes. As Vlad had pointed out I have to make some changes to get balance. When the threat of cold weather is over and time allows I think a larger evaporator and anti-freeze.

Thanks Guys
Randen

[AC_Hacker]

Originally Posted by randen

As Vlad had pointed out I have to make some changes to get balance.

Great report back.

-AC

[pachai]

Thanks everyone, it's always great reading about things people have tried that worked or taught them something.

Some time ago (about 2 years?), someone posted a picture of an air conditioner with a plexiglass box around the the heat exchanger, filled with water.

I don't remember if it was real or just proposed...Did anyone do something similar? (Did it work? :-)

I have a couple of hydronic heat exchangers installed, so all I need to do is make cold water...

Even if the hot side will be air source for the current season, it will help.

As for the "ground" or "Water" Source...

Has anyone tried anything with open loop?
I think I can easily get the flow I need for a reasonable cost, but I'm not sure I can get rid of the water. It seems the EPA has rules about Injection Wells.

If I were to use the well for driking water
also ( a few gallons a day), I would not want to dump the geo water back in there.
(And the drinking water helps offset drilling cost).

Any experiences here would be great.

Thanks
Seth

[Vlad]

Originally Posted by pachai

.....I have a couple of hydronic heat exchangers installed, so all I need to do is make cold water...

Even if the hot side will be air source for the current season, it will help.

As for the "ground" or "Water" Source...

Can you provide more details? Like heat/ cool load expected, temperature range, etc the more the better, don't worry we will read it all

Originally Posted by pachai

Some time ago (about 2 years?), someone posted a picture of an air conditioner with a plexiglass box around the the heat exchanger, filled with water.

How critical is to have XE in plexiglass box ??

[pachai]

Originally Posted by Vlad

Can you provide more details?...

How critical is to have XE in plexiglass box ??

Thanks for offering to help.

I don't have much info yet.
Based on commercial geo estimates,
I need somewhere between
4 and 8 tons. I need to look again
to see if two or more are close.

I have not had a chance to run my own numbers, but gas consumption last year points to about 3 tons.
The occupied part of the house
is 2000 SF, though many areas don't
actually need heat/cool - eg, rooms
with no outside walls - never heated
before, no need now.

I have a "2 ton" unit in the
Kitchen/Dinette and a 3/4 ton unit
in the bedroom.
These are different models of
Multi-Aqua hydronic air handlers.
Give it power, it moves air,
and sends a demand for water
flow (24VAC).


The idea that I saw on this forum
and that I liked was taking a window air conditioner (and I have a few that are large), remove all the plastic housings
and insulation, and fan, and make a
storage tank around the heat
exchangers on both sides.

I have an AC that has a bad fan, so I thought I would use that, but the compressor is flakey also, so I am looking at another. This is one that some buffoon dropped on the power switch, so the post broke off. That gives this buffoon an excuse to change all the wiring.
The EER on this one is higher, 10.8 or so.


I have 2-3 options before me for ground:

As for ground, I got an estimate for the whole house, of about $80,000, including 700' of bore holes. The holes were quoted at $17,000. With Natural gas
heat, the 80,000 figure is hard to
justify.

So I got a quote from a paving contractor
to dig trenches for me to install
3 Tons worth of horizontal slinkies
(3 * 500' of 3/4" HDPE) including 6" of
sand above and below each,
for $6,000. I'm planning to ask him
to quote paving as well.


I also got an estimate (but first hand
or in writing) for a well for $4,000.
That would be for pump-and-dump.
But I still need to speak to the city
plumber about the dump part.


Other initiatives include
solar thermal collectors -
There are a few options, and
parabolic trough is ranking up there.
I'm also thinking of a flat panel
that will blend with my solar panels.

I have two 40-gallon hot water tanks.
One is electric, and worked fine
for my radiant floors this winter;
The other is gas and does not work.
(Well, my sister-in-law gave up on it).


Thanks
Seth

[MN Renovator]

"As for ground, I got an estimate for the whole house, of about $80,000, including 700' of bore holes. The holes were quoted at $17,000. With Natural gas
heat, the 80,000 figure is hard to
justify."

$17k is how much it costs just for a GSHP dig? Wow! The payoff period would be longer than a 30 year mortgage. For my house and my NG and electric rates, I'd be dead by the time that would pay off.

[pachai]

I didn't include the climate in my post...
I am in Northern NJ. This week,
it was 70 degrees at 6:30 am.

I believe I am just 35 feet above
the water table. I have one neighbor
who has a well. He replaced the pump
since he bought the house, and said
it is a 200' well. I believe the
elevation is the same, so the well
would be the same.
I have a friend who did lab
work on the well water
(he is a chemistry professor).
I can find out if they have
the flow rate of the well.


Thanks
Seth

[charlesfl]

correction Question for AC Hacker or anyone interested in refrigerants.

Is R22a suitable for use in a home heat pump? The reason I am asking is my understanding is that it is made from propane which is flammable and may not be legal in the US. I haven't verified that.

Also, is R22a any better than propane run through a double filter and a reclaim machine? I have not been able to find the complete specifications on R22a. I found the specifications for R290 on the Linde Group refrigerants. Seems we could make our own to these specifications.

Thanks for your help Charlesfl

[AC_Hacker]

Originally Posted by charlesfl

Is R22a suitable for use in a home heat pump? The reason I am asking is my understanding is that it is made from propane which is flammable and may not be legal in the US. I haven't verified that.

R22a is flammable. I'm not sure if it is propane, but the PT curves map one upon the other.

Originally Posted by charlesfl

Also, is R22a any better than propane run through a double filter and a reclaim machine? I have not been able to find the complete specifications on R22a. I found the specifications for R290 on the Linde Group refrigerants. Seems we could make our own to these specifications.

BradC has done some very interesting work on this issue. Do a search in the Geothermal topic for BradC.

In terms of legality, R22 and R12 were legal for many years although they did measurable damage to the ozone layer. R22 and R12 are both patented substances, and made very large profits for the companies that hold these patents. About the same time that R22 and R12 were invented, the organic, non-patentable substances were made illegal... curious, huh?

R22 and R12 were replaced with other synthetic, patented substances that do not damage the ozone layer, but cause very long-lasting damage due to global warming.

Organic refrigerants cause no ozone damage and no global warming harm... and are illegal in the USA.

-AC

[Mobile Master Tech]

Read the whole manifesto including poring over linked info-wow! AC and others, thanks for your info and dedication.

I'm a master automobile technician and part time inventor/tinkerer/problem solver. I'm not afraid to spend money when needed, but I would much rather save it!!

I believe in "prudent consumption", meaning balancing a fulfilling Western lifestyle with ecological responsibility and as little waste as possible. A great quote-We will NEVER run out of oil!!! However, we ran out of $10/barrel oil a long time ago, we've run out of $75/barrel oil too. Someday we'll run out of $300/barrel oil, and so on. Our problem isn't energy-as long as the sun shines, we will have a limitless supply. It's conserving our high grade energy sources that we are burning through in a geological blink of the eye instead of using the lowest grade energy source that can do the job. It's raining soup, we need the technology (or grassroots methods!) to capture it in all the forms it comes in.

My personal ecorenovator projects include:
1: Zoned open loop radiant floor system with 12 watt circulator pumps (variable speed ECM motors). Yes it's safe-and staple up is working beautifully even on (rare) 14F nights thanks to transfer plates and 130-140F water.
2: Zoned ductwork upgrades, hospital grade air filtration with low pressure loss and a Nordyne inverter drive 22 SEER air conditioning system with a desuperheater hack for heat reclamation and evaporative cooling for the last portion of the condenser coil.
3: Evacuated tube solar thermal collectors & controller-1/2 of normal output even in full cloud & low temps!
4: Hacked homebuilt geothermal heat pump of 1-1.5 ton capacity operated by solar controller when needed. My research is ongoing about using R290 fortified R134a refrigerant and ejector-type expansion device.
5: 2000 gallon stratified homebuilt heat storage tank with plenty of room for phase change modules to buffer heat sources/loads and provide that 130-140F water for heating/DHW at the top of the tank while having 90-110F supply water for heat sources.
6: Underslab heat injection timed to arrive back to slab approx 6 months later.
7: Supported extension ladder/winch/power auger drill rig to place ground loops in pattern around house tha can also recapture any "escaping" heat from underslab injection.
8: Sealing, homebuilt HRV/ERV, low-e windows, thermally reflective roof, etc. etc.
9: Haven't thought it up yet, but the first 8 are plenty for now!!

More posts to come. Glad to meet all of you!!
Craig