12kbtu heat pump

Fordguy64 · 07-11-17, 12:40 PM

Ok so I'm starting a thread to be more specific to my first refrigeration system hack.

I have 2 12kbtu compressors. 1 is an r22 unit and the other is r134a. I plan to use the r22 unit and swap it over to r290. I would like some help sizing the brazed plate heat exchangers(or coax) so I can start keeping an eye out for good deals.

Also I work with a guy who is an electronics engineer and loves playing with arduinos and raspberry pi's so I lm going to ask for his help with the controls. I have some very fancy flow control valves that are good for 2000psi and really high and low temps. I want to make an electronic expansion valve with one of these flow meters and a stepper motor.

My next question is what parts of the system do I want to monitor to control the exv? Pressures on high and low? Temps in and out of hi and low sides? Amp draw of compressor?

07-11-17, 12:40 PM	#1
Fordguy64 Journeyman EcoRenovator Join Date: Oct 2011 Location: Cincinnati ohio Posts: 338 Thanks: 40 Thanked 35 Times in 31 Posts	12kbtu heat pump Ok so I'm starting a thread to be more specific to my first refrigeration system hack. I have 2 12kbtu compressors. 1 is an r22 unit and the other is r134a. I plan to use the r22 unit and swap it over to r290. I would like some help sizing the brazed plate heat exchangers(or coax) so I can start keeping an eye out for good deals. Also I work with a guy who is an electronics engineer and loves playing with arduinos and raspberry pi's so I lm going to ask for his help with the controls. I have some very fancy flow control valves that are good for 2000psi and really high and low temps. I want to make an electronic expansion valve with one of these flow meters and a stepper motor. My next question is what parts of the system do I want to monitor to control the exv? Pressures on high and low? Temps in and out of hi and low sides? Amp draw of compressor?