Most efficient heat pump vc. geothermal

[Barmaley]

Hi everyone,

I am so glad that I found this forum - I hope to learn a lot here!

I live in PA, USA and I have about 4500 SF house which I heat and cool with electric baseboard and window air conditioners. I am an electrical engineer and my company upgrades commercial and industrial lighting to make it energy efficient. I am tired of paying high electric bills and decided to upgrade my in-house HVAC system to the most modern state. I made some research on the web and became completely confused on the way to go. So I need your advice.

My first intention was to go with standing column geothermal system as it seems to be the most efficient option. However I have found that there is Europe they use heap pumps based on copeland compressors with EVI technology. Those are capable to achieve COP of over 4 for low temperatures as of - 15C. Then I have found a Chinese company claiming a geothermal unit EVI achieving COP 7 if you can believe them.

Another problem was to find a unit designed for USA market: for some reason all AVI based heat pumps are made for Europe. The problem with is that they are Air to Water, while here we use Air to Air systems to use it for both heating and cooling.

What would you suggest for my application? Air heat pump of geothermal? What brand? Can I safely buy directly from Chinese companies? Thank you in advance!

Barmaley

[Bigfreeze]

Do not buy chinese. If you want to rid yourself of 4 or 5 grand that badly post it to me instead. I'd go for a true geothermal unit, borehole type with a passive cooling HX. You'll get high COP's (definitely over 4, possibly as high a 5.5, depending on the unit and water temp required) in winter and cheap cooling in summer. You'll only need to run the circulating pump. If I were to move to the states or Australia in the morning that is the business I would set up in the morning.
If you can't find a good european heat pump to suit you, you could email Mike Holm who posts here and he might be interested in building one for you.

[Barmaley]

If I would like to go with an professionally manufactured heap pump, what is the most efficient model designed to work between -15C to 45C ?

[Bigfreeze]

If I would like to go with an professionally manufactured heap pump, what is the most efficient model designed to work between -15C to 45C ?

Don't know which units are available in the US. If you give me a list of names you're looking at I'll recommend one. European systems will be ahead so look towards those manufacturers. The outside temp has virtually no influence on the performance of a borehole system.