The Homemade Heat Pump Manifesto

[AC_Hacker]

Hi, sparkchaser,

Originally Posted by sparkchaser

...Has anyone successfully used an air-source heat pump converted themselves to ground-source?...

(In a way, that's what I have done, but my donors are in truth de-humidifiers, which is more or less air to air.)

There have been some folks on this blog who have put such an idea forward, but I don't know of anybody who has attempted it.

As you probably know, there are

• single-speed ASHP compressors
• dual compressors
• variable-spreed compressors

The single-speed compressor would be the easiest to do, and would pretty much consist of replacing the evaporator coil with an equal capacity liquid-to-refrigerant heat exchanger, and in place of the fan, you would need a properly-sized circulation pump... not so hard to do. As you might have seen, I tend to be pretty fond of brazed plate heat exchangers, but if you have a line on cheap copper tubing, you might be able to make a tube-in-tube that would do it. I have not yet located information that would help me size a tube-in-tube refrigerant-to-water exchanger.

You can find new and used heat exchangers on ebay at reasonable prices. Most give specs for water-to-water, which is not the same as refrigerant-to-water.

A super cool hack would be to convert an inverter technology mini-split to ground source. There are significant technical hurdles with regard to the inverter technology & ECM fans (ECM pumps?), but the efficiency would be stellar.

Is this the kind of info you are looking for?

-AC_Hacker

P.S.: How far up river are you?