EcoRenovator - View Single Post - Propane (R-290) for heat pumps?

Thepprof · 07-27-12, 05:37 AM

I recently posted several notes; regarding how to add Propane to my Klimeair minisplit. I literally got no feedback other than the probability that R290 is compatable with the oils in a R410a system. I thought my 12K unit was junk and rather than waste R410a which I did not have at the time used propane to get the unit up and running. I vacuumed, and then started adding propane to the unit set up in my shop. The first run resulted in the metering device frosting up big time. I cotinued adding gas and forced the frosted area up the 15 ft. of supply lines into the air handler. I ran these tests over several days and managed to get a steady 10 degree difference at the air handler and on one test managed a 20 degree difference. My other good unit shows a 30 degree difference on a 90 degree ambient day. I decided that the unit was actually a working unit and decided to convert it back to R410a. My refigeration guy would not touch the device because he could not do the usual sub/super heat process. Once again I took a shot in the dark. Turned the gas tank upside down to feed liquid into the unit and guessed at the amount. When I started the unit the metering device immediately frosted up. I once again slowly added R410a and pushed the frost up into the air handler. at 120 psi gas line pressure I'm getting 20 degree difference at the air handler. The Klimeaire rep finally told me that on a hot day I should shoot for 140 psi on the gas line. For those interested parties it seems that somewhere there is a chart relative to each device that you can use to top off the system at a given temperature. I'm assuming that this works if the device like mine is all new with no screwups anywhere in the system. I will have to get a new low pressure gage and increase the gas line pressure to 140 and see if I can once again get that aloof 30 Degree Delta T.

07-27-12, 05:37 AM	#189
Thepprof Lurking Renovator Join Date: Jun 2012 Location: Virginia Posts: 28 Thanks: 0 Thanked 4 Times in 3 Posts	I recently posted several notes; regarding how to add Propane to my Klimeair minisplit. I literally got no feedback other than the probability that R290 is compatable with the oils in a R410a system. I thought my 12K unit was junk and rather than waste R410a which I did not have at the time used propane to get the unit up and running. I vacuumed, and then started adding propane to the unit set up in my shop. The first run resulted in the metering device frosting up big time. I cotinued adding gas and forced the frosted area up the 15 ft. of supply lines into the air handler. I ran these tests over several days and managed to get a steady 10 degree difference at the air handler and on one test managed a 20 degree difference. My other good unit shows a 30 degree difference on a 90 degree ambient day. I decided that the unit was actually a working unit and decided to convert it back to R410a. My refigeration guy would not touch the device because he could not do the usual sub/super heat process. Once again I took a shot in the dark. Turned the gas tank upside down to feed liquid into the unit and guessed at the amount. When I started the unit the metering device immediately frosted up. I once again slowly added R410a and pushed the frost up into the air handler. at 120 psi gas line pressure I'm getting 20 degree difference at the air handler. The Klimeaire rep finally told me that on a hot day I should shoot for 140 psi on the gas line. For those interested parties it seems that somewhere there is a chart relative to each device that you can use to top off the system at a given temperature. I'm assuming that this works if the device like mine is all new with no screwups anywhere in the system. I will have to get a new low pressure gage and increase the gas line pressure to 140 and see if I can once again get that aloof 30 Degree Delta T.