Homemade 2 ton HP, air to water now, DX in future

vlada33 · 01-11-20, 03:24 PM

Hi people,

I'm sorry if my English isn't perfect...

Just to say few words about my project that it's in progress for some time now. First of all I find some scrap AC 21000btu cooling and 23500btu heating. Indoor unit was damaged and price was low for that reason, and because it can be used like it was made I dexide to take outdoor unit and make HP from it. Reason why HP need to be air to water or direct expansion to water is that houses in Europe usually are made from bricks and concrete and walls are not empty so tunnels for heating and cooling are not possible to made when house is already made. In my case house is almost been finished, and I lose option to make a floor heating (that will be best option in my case) so in this setup I will try panel radiators and fancoil radiators.

Outdoor unit using R407c, in this moment i'm think that it's little low with refrigerant, indoor exchanger freon to water is swep b25th and it's possible that is undersized for power that HP produce.

I have many pictures and i will post it soon, but first to say few more words about problems I have with it, maybe someone is HVAC technician and can help...

Problem that I have is low temperature water, freon temperature is ok, it will be few degrees higher when I add refrigerant to normal level but even than I will be low for 5-8 degree Celsius(that is somewhere about 10-15F I think) , and difrence between temperature of freon and water is to big, about 10 degrees Celsius

Solutions that i'm think about

1.Changing exchanger for bigger one, maybe will bigger excanger give few degrees extra...

2 Maybe just to somehow get more heat from freon, and that is going in few ways,

is it ok to put more R134a to mixture of R407c (R134a on same pressure has much bigger temperature than clean R407c) so can I expect that I get lets say 5 degrees more with that mixture?

Maybe to change refrigerant and use R22 (bad for environment but better heating) maybe this is last option I don't like to destroy nature?

Or maybe to change refrigerant to R290, also better temperature but its flammable and I'm not sure how will compressor will react?

I hope that post will not tired you with reading, and I'm apology for very very long post...

01-11-20, 03:24 PM	#1
vlada33 Lurking Renovator Join Date: Oct 2019 Location: Europe, Serbia Posts: 7 Thanks: 1 Thanked 0 Times in 0 Posts	Homemade 2 ton HP, air to water now, DX in future Hi people, I'm sorry if my English isn't perfect... Just to say few words about my project that it's in progress for some time now. First of all I find some scrap AC 21000btu cooling and 23500btu heating. Indoor unit was damaged and price was low for that reason, and because it can be used like it was made I dexide to take outdoor unit and make HP from it. Reason why HP need to be air to water or direct expansion to water is that houses in Europe usually are made from bricks and concrete and walls are not empty so tunnels for heating and cooling are not possible to made when house is already made. In my case house is almost been finished, and I lose option to make a floor heating (that will be best option in my case) so in this setup I will try panel radiators and fancoil radiators. Outdoor unit using R407c, in this moment i'm think that it's little low with refrigerant, indoor exchanger freon to water is swep b25th and it's possible that is undersized for power that HP produce. I have many pictures and i will post it soon, but first to say few more words about problems I have with it, maybe someone is HVAC technician and can help... Problem that I have is low temperature water, freon temperature is ok, it will be few degrees higher when I add refrigerant to normal level but even than I will be low for 5-8 degree Celsius(that is somewhere about 10-15F I think) , and difrence between temperature of freon and water is to big, about 10 degrees Celsius Solutions that i'm think about 1.Changing exchanger for bigger one, maybe will bigger excanger give few degrees extra... 2 Maybe just to somehow get more heat from freon, and that is going in few ways, is it ok to put more R134a to mixture of R407c (R134a on same pressure has much bigger temperature than clean R407c) so can I expect that I get lets say 5 degrees more with that mixture? Maybe to change refrigerant and use R22 (bad for environment but better heating) maybe this is last option I don't like to destroy nature? Or maybe to change refrigerant to R290, also better temperature but its flammable and I'm not sure how will compressor will react? I hope that post will not tired you with reading, and I'm apology for very very long post...