DA-13-C003 -- Application of a Linear Fit Rating Method for Mixed Single-Speed Unitary Air Conditioners

A method employing the simultaneous solution of two linear fits is used to determine the rated cooling capacity and seasonal energy efficiency ratio, SEER, of outdoor unit and indoor unit air-conditioner combinations not previously tested as a complete system. The information presented here outlines the formulation, verification, and application of the method to produce ratings. For the examples presented here, the calculated cooling capacity and SEER ratings were within plus or minus 5 % for four of eight and plus or minus 5 % for six of eight mixed systems, respectively, compared to test data. This method applies to split system residential air-source unitary air conditioners and heat pumps operating in the cooling mode, employing a single-speed, single-phase compressor. The rated cooling capacity of the highest sales volume combination used in obtaining the ratings of the mixed system must be less than 19 050 W (65 000 Btu h-1).