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Steve W. and others with an interest in geothermal
heat pumps,
Before I start let me say that I neither own stock
in or work for Nyle. This will be my last off topic post on the matter of
heat pumps. If you have questions either send me an e mail or go to the
Nyle web site.
I am very interested in the Nyle technology
though. They are developing a Cold Climate Heat Pump (CCHP) boiler.
I have wanted to get rid of my boiler for 15 years, but my baseboard heated
house cannot affordably be fitted with hot air ducts. Now here comes Nyle
with a heat pump that looks like it can heat water to 103 deg F just for
baseboard heat. I want to say goodbye to my noisy boiler, the ash dust
from burning oil, and the oil tank in my garage that takes up space where I want
my air compressor.
The limitations of today's standard non-geothermal
heat pumps have to do with the freons available and the limitation of the
compression ratio available in a single compressor. Thermodynamically
having a heat source at 55 deg F (geothermal ground) is only about 12 % more
efficient than having a heat source at 0 deg F. The Nyle has two
compressors staged, so the compression ratio of the system is theoretically the
compression ratio of the compressors multiplied by each other.
All I was trying to point out is that Nyle's CCHP
is so much more efficient than a standard heat pump at 0 deg F that it
approaches the efficiency of a geothermal heat pump even at 0 deg F. But
with a geothermal heat pump you have multiple wells or multiple trenches with
buried tubing. If you were to invest the difference in the installed cost
between a geothermal and a CCHP you would pay for the additional electric to run
the CCHP.
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