ECONOMIC ANALYSIS
Economic analysis is performed on an 85% undercharged
system which can produce cooling effect but inefficiently.
From the experimental results carried out under the standard
condition (95°F dry bulb, 75°F wet bulb) it was found that
the EER (or COP) for such a system decreases by about
56%. Thus, at other ambient conditions the same decrease
in EER is assumed.
Calculations are based on a 3 ton residential airconditioning
unit (Carrier model 50QJ004). The EER data
for the cooling performance of such a system was obtained
from the manufacturer. It is assumed that tlie 3 ton unit is
sized to provide the complete design load of 36.OOO Btuih
with a temperature difference of 20°F (95°F dry bulb
outside, 75°F dry bulb inside). Thus, the total annual energy
consumption ofa fully charged and an undercharged system
is estimated by Bin Method as