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Measured Effects of Retrofits - A Refrigerant Oil Additive and a Condenser Spray Device - On the Cooling Performance of a Heat Pump
Abstract
A 15-year old, 3-ton single package air-to-air heat pump
was tested in laboratory environmental chambers
simulating indoor and outdoor conditions. After
documenting initial performance, the unit was retrofitted
with a prototype condenser water-spray device and
retested. Results at standard AM cooling rating
conditions (95°F outdoor dry bulb and 80167 OF indoor
dry bulb/wet bulb temperatures) showed the capacity
increased by about 7%, and the electric power demand
dropped by about 8%, resulting in a steady-state EER
increase of 17%. Suction and discharge pressures were
reduced by 7 and 37 psi, respectively.
A refrigerant oil additive formulated to enhance
refrigerant-side heat transfer was added at a dose of one
ounce per ton of rated capacity. and the unit was tested
for several days at the same 95°F outdoor conditions and
showed essentially no increase in capacity, and a slight
3% increase in steady-state EER. Adding more additive
lowered the EER slightly. Suction and discharge
pressures were essentially unchanged.
Our short-term testing showed that the condenser-spray
device was effective in increasing the cooling capacity
and lowering the electrical demand on an old and
relatively inefficient heat pump, but the refrigerant
additive had little effect on the cooling performance of
our unit Sprayer issues to be resolved include the effect
of a sprayer on a new, high-efficiency air conditioner/heat
pump, reliable long-term operation, and economics.
Citation
Levins, W. P.; Sand, J. R.; Baxter, V. D.; Linkous, R. S. (1996). Measured Effects of Retrofits - A Refrigerant Oil Additive and a Condenser Spray Device - On the Cooling Performance of a Heat Pump. Energy Systems Laboratory (http://esl.tamu.edu); Texas A&M University (http://www.tamu.edu). Available electronically from https : / /hdl .handle .net /1969 .1 /6670.