All Temperature Heat Pump

Has it really been a year since I last posted? I guess I've been busy!
This past year has been spent doing comprehensive home energy audits, a job I couldn't love more. Every home has serious energy efficiency issues - air leaks, poor insulation, old heating/cooling systems. The amount of wasted energy is stunning and disheartening.

Here are some of the highlights of the past year:
Continued success with my own home's geothermal heat pump
I use the Earthlinked system, from ECR Technologies, to heat and cool my home. This ground source heat pump bypasses the complexity of a normal ground source heat pump and uses direct exchange of heat using refrigerant lines buried in the ground. Normal GSHP systems run anti-freeze through plastic ground loops to exchange heat with the earth. This requires additional pumping, which uses more electricity. Moreover, plastic is a poor heat exchange medium.
Because the Earthlinked system runs the refrigerant directly into the ground, there is no intermediate transfer and therefore none of the efficiency robbing heat exchangers, plastic pipes and pumps.
Even better, because the system is simpler than most, its cost tends to be lower than others. So, not only do you pay less to operate it, you pay less up front for installation. Overall, this is a fantastic system

The All Temperature Heat Pump by Hallowell
Recently, I learned that Hallowell is selling their heat pump technology on the mass market. This air source heat pump has truly amazing performance.
Designed in Maine, for cold climates, the Acadia has multiple compressors, allowing it to pump out near its rated heat at 0F. Additionally, it puts out hot air, unlike conventional air-to-air heat pumps. The air coming out of a Hallowell is about 120F, so it feels toasty too.
While it's much more expensive than a conventional heat pump, the year round operational costs are much lower. Plus, in most areas, it's less expensive than a GSHP, because the installation doesn't require drilling wells or tearing up your yard. So, while it isn't as efficient as a GSHP, it gives the benefit of cold climate heating at a much lower cost. This is a truly excellent technology.

There's so much more. It's really an exciting (and frightening) time to be doing sustainable building.