Project Title:

Non-Azeotropic Heat Pump for Crew Hygiene Water Heating

09.04-3200
Non-Azeotropic Heat Pump for Crew Hygiene
	Water Heating
Foster-Miller, Inc.
350 Second Avenue
Waltham, MA 02254
David H. Walker  (617-890-3200)
MSFC -- NAS8-37624

Abstract:

	 One of the power consuming systems required by the Space Station is the heating
of water for crew hygiene, which may be accomplished through the use of an electric
resistance heater or a heat pump. Of the two, the heat pump offers the most efficient
operation by utilizing available waste heat sources. Performance of the heat pump
can be improved through the use of a non-azeotropic refrigerant mixture as the working
fluid.
	For the Phase I effort, a heat pump operating with a working-fluid mixture of 70
percent R-11 and 30 percent R-22 was investigated through the construction and successful
testing of a bench-scale unit. Experimental results showed a significant increase
in coefficient of performance when compared to a heat pump using R-12 as the refrigerant.
The benefits that can be achieved by the use of this heat pump were estimated to
be a reduction in power demand from 46 kW to 450 W and an annual electrical energy
savings of 2,044 kWhr. The value of these savings was calculated to be $429,240 per
year.

Potential Commercial Application:

Potential Commercial Application: Non-azeotropic refrigerant mixtures could be applied
successfully to commercially available heat pumps now used in many heating, ventilating,
air conditioning, and water heating applications.