Visit the Energy Systems Laboratory Homepage.
An Evaluation of Improper Refrigerant Charge on the Performance of a Split System Air Conditioner with a Thermal Expansion Valve
Abstract
The effect of the improper charging on steady state and
cyclic performance (capacity, EER, power consumption, SEER,
and coefficient of degradation) of a residential air
conditioner which utilized a thermal expansion valve was
investigated. This study was the continuation of
ESL/CON/88-1 performed by Mohsen Farzad and Dennis O'Neal.
A fully charged condition was established as a base case.
The full charge was obtained by charging the unit to the
subcooling specified by the manufacturer for a specific
indoor and outdoor temperatures. Once the full charge was
determined, the unit was subjected to 40%, 30%, 20%, 15%,
10%, and 5% undercharging and 5%, 10%, 15%, and 20%
overcharging of refrigerant by mass. The fully charged
tests were compared to those for under and overcharging.
The performance of the unit was evaluated as a function of
charge as well as at four outdoor room temperatures (82°F,
90°F, 95°F, and 100°F). As the outdoor temperature
increased, the total capacity and EER dropped. The maximum
total capacity, EER, and SEER were found at 10%
undercharging (12 6 oz). The capacity and efficiency (EER
and SEER) of the unit were found to be less sensitive to
under/overcharging than the unit with a capillary tube
expansion previously studied. Other data such as refrigerant flow rate, sensible heat ratio, superheat and
subcooling were also presented.
Subject
improper chargingCollections
Citation
Farzad, M.; O'Neal, D. L. (1989). An Evaluation of Improper Refrigerant Charge on the Performance of a Split System Air Conditioner with a Thermal Expansion Valve. Energy Systems Laboratory (http://esl.tamu.edu), Texas A&M University; Department of Mechanical Engineering, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /2089.