Challenges in Developing Environmentally Safe Heat Pumping Systems.
Challenges in Developing Environmentally Safe Heat
Didion, D. A.; Brown, J. S.
ZSITS International Thermal Science Seminar, American
Society of Mechanical Engineers (ASME) Proceedings.
June 11-13, 2000, Bled, Slovenia, 1-10 pp, 2000.
heat pumps; heat pumping systems; environmentally safe;
refrigerants; halogens; thermodynamics; ammonia;
hydrocarbons; carbon dioxide; water; air
The advent of the global warming crisis has brought
about a viewpoint, in many governments, that the halogen
family of refrigerants should be replaced, in part or in
toto, by the so-called natural refrigerants. For this
proposal to be valid it is necessary to consider both
the refrigerant's direct environmental impact and its
life-long performance under field conditions. This is
particularly true in the case of global warming because,
for most applications, it is the heat pump's operating
efficiency and its impact on the central power plant's
emissions that is the dominating environmental factor.
Any refigerant must also meet a variety of other
criteria that deal with durability, safety and costs. A
simple comparison of basic fluid properties is conducted
to indicate what system design considerations must be
made if a refrigerant is to become an acceptable
alternative. It is also reasoned that while computer
models and laboratory prototypes are a necessary
beginning, they are not sufficient to determine the true
environmental impact of any system. Finally, the
question is raised as to whether the refrigerant
specification approach is the better path to an improved
environment or if it is wiser to leave all options open
for researchers and manufacturers to meet an
environmental performance standard any way they choose.