DIY heat pump??

[conradpdx]

Nice to see the experiment working for you. And glad to hear you already got the pipes in your basement.

I like the the little water unit two. The combination of those two posts do get the wheels turning a little but I'm not sure where the gyroscope will end up at this point.

Keep it up I,m looking forward to the upcoming posts.

[Xringer]

The floor downstairs is still 64.8 and holding steady.

I took the AC downstairs this morning (it's 66 right now) and ran it on the floor for about 20 minutes, set to 65 degrees.
Since it was just pumping heat from the the front to the back, there wasn't any heating or cooling, just some dehumidifying.
Since the coldest air down there is right on the floor, it was a good test to make sure the compressor would come on and stay on.

My test plan is to mount the AC in the wall of the little Landry room.
I'll make a strong platform five feet off the floor, and cut the AC
hole-in-the-wall as large as needed.

The basement intake air 5 feet up will be warmer.. And the cold output air
will sink to the floor.

I'll post again when I've done some more work.

[Xringer]

Did a little testing today and posted it here:

Off Topic Lounge: Yet another heat pump test

[briansailing]

I am doing the same thing with a window unit. I will be disassembling and building my own control unit to allow for regeneration once the coil frezes in the winter.

I will update soon.

[Xringer]

Where are you going to get your air source? I think my plan to use the basement air might be limited to under 10,000 BTU..
So, I've been thinking about using outdoor air (like a regular heatpump) and only using it on mild days..

The Airtap HWHP at Airgenerate.com | Adaptive Energy Solutions


seems to do okay down to 32 deg, but I'm pretty sure it's going to get frosted over..

The basement air would be pretty dang cold if you installed 4 or 5 AirTap units in your basement..

[NiHaoMike]

Originally Posted by Xringer

There's a mistake in that picture. The small cylinder next to the compressor is the accumulator, not the expansion valve. The expansion valve is in the line connecting the condenser to the evaporator.

[Xringer]

I was looking at that before and couldn't figure out the gas routing..
Since it didn't look anything like the basic diagram..


What is the expansion valve anyways? Just a tight spot in the pipe?
Could a cut-off valve be used? Have it open part way?

[duaneb9729]

the expansion valve is a device that meters the flow of refriderant to allow for the maximum amount of cooling/humidity removal.

conradpdx, very little copper is involved in a in ground heat pump system, lots and lots of pex pipe is used for the transfer of heat from the ground to the heat pump.

i personaly have a carrier air to air heat pump, rated at a 16 on the seer rating scale and mated to a two stage variable speed 95% efficient furnace, this will be my first winter with a heat pump.

i have the controls set up to change over to the furnace at 30 degrees, air to air heat pumps are way better than they used to be. but still have a ways to go, i am experimenting at my own home, i am a heating and a/c contractor.

and as the technolgy improves we will move into the ground source heat pumps today it requires a very very large investment and so far would be a wonderful investment for the next home owner! but yes they do work

one of the troubles with converting a window unit to use as a heat pump, is what to do with the excess refriderant and installing the reversing valves and other electronic controls, a very expensive task and possible for an experianced heating person to do but with much effort.

[Xringer]

"installing the reversing valves"..

Wouldn't those valves be unnecessary for heat-only system?

I've heard that the direct exchange type ground loop systems use copper in their
ground loops. That must be the best stuff to use, if you're pumping refrigerant into the ground loop.

[briansailing]

http://www.ornl.gov/~webworks/cppr/y...res/113424.pdf


By adding heat to the accumulator you can prevent frosting. I am purchasing several programmable temperature relays to allow control of the fan, compressor, and new accumulator heater.

Will be working on this over the weekend.

Brian