EcoRenovator - View Single Post - Anybody ever build a natural gas heat pump?

MN Renovator · 11-09-14, 08:23 AM

Automotive air conditioning has a reputation for being very inefficient, a COP of between 1 and 2 is common. 7kw output is about 2 tons. A COP of 2 is 6.824 EER.

Here's a performance chart. It's not pretty.
http://www.sanden.com/objects/SD7H15_Performance.pdf

I think I'd rather run a cogeneration generator(important that it isn't oversized but can still handle the startup load) that is installed inside the house to run a mini-split heat pump. Not sure if they are okay with running off generator power or not so maybe you are stuck with a conventional compressor if you decide to go that route.

You could use automotive equipment, don't get me wrong. I'm thinking there's a better way to go about this.

I personally think your best bet is to run the heat pump off of grid electricity if it is available. I'd expect it to be cheaper, cleaner, and quieter than running an AC compressor off of anything other than electricity.

Either way, good luck.

11-09-14, 08:23 AM	#3
MN Renovator Less usage=Cheaper bills Join Date: Nov 2010 Location: Minneapolis, MN Posts: 939 Thanks: 41 Thanked 116 Times in 90 Posts	Automotive air conditioning has a reputation for being very inefficient, a COP of between 1 and 2 is common. 7kw output is about 2 tons. A COP of 2 is 6.824 EER. Here's a performance chart. It's not pretty. http://www.sanden.com/objects/SD7H15_Performance.pdf I think I'd rather run a cogeneration generator(important that it isn't oversized but can still handle the startup load) that is installed inside the house to run a mini-split heat pump. Not sure if they are okay with running off generator power or not so maybe you are stuck with a conventional compressor if you decide to go that route. You could use automotive equipment, don't get me wrong. I'm thinking there's a better way to go about this. I personally think your best bet is to run the heat pump off of grid electricity if it is available. I'd expect it to be cheaper, cleaner, and quieter than running an AC compressor off of anything other than electricity. Either way, good luck.