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Reliability of Heat Pumps Containing R410-A Refrigerant
Abstract
As a result of the Montreal Protocol in
1987 and subsequent approval of the U.S. Clean
Air Acts, air conditioning manufacturers in the
United States may not produce new products
containing Hydrochlorofluorocarbons or HCFC
after 2010 because of their potential destruction
of ozone in the troposphere. Residential and
commercial rooftop units usually contain
hydrochlorofluorocarbon 22 , (also referred to
as HCFC-22 or R-22). R-22 has been used
successfully as a refrigerant in HVAC
equipment for over 40 years. High volume
production through these years has helped
manufacturers to produce reliable products. R-
4104 a hydrofluorocarbon (HFC) mixture, is a
leading candidate to replace R-22 in residential
and light commercial air conditioners and heat
pumps. Most manufacturers do not have enough
experience using R-410A to confidently design
and build reliable R-410A units.
The HVAC industry joined together in
1992 by forming AREP, Alternate Refrigerant
Evaluation Program, to share pre-competitive
data on alternate refrigerants. One major
manufacturer announced a formation of black
smudge on internal surfaces of field trial units
using HFCs. Several causes were suggested but
none were published. Reports of capillary tube
plugging were wide spread. Polyol Ester (POE)
oils used with HFC refrigerants will break down
into acid and alcohol when exposed to heat.
Manufacturers have many tools to
establish reliability of a product prior to mass
production. Units and compressors can be nm
on life tests. Prototype test units can be built in
the factory and then installed in the field by
service technicians. Examples and results from
these techniques are described within the paper.
Citation
McJimsey, B. A.; Cawley, D. (1998). Reliability of Heat Pumps Containing R410-A Refrigerant. Energy Systems Laboratory (http://esl.tamu.edu); Texas A&M University (http://www.tamu.edu). Available electronically from https : / /hdl .handle .net /1969 .1 /6714.