William V. Payne

A comparison of rating water-source heat pumps using ARI standard 320 and ISO standard 13256-1

This investigation compares performance ratings obtained when testing water-source heat pumps using the Air-Conditioning and Refrigeration Institute (ARI) Standard 320 and the International Organization for Standardization (ISO) Standard 132561. Multiple tests included a ducted 1.75 kW (0.5 ton) unit and a non-ducted 3.52 kW (1.0 ton) unit. Air external static pressure and water flow were varied at the ISO conditions to determine the correction in capacity and total power mandated by the ISO standard. ISO cooling capacity for the first and second units were 0.1 % higher and 1.1 % lower than the ARI capacity, respectively. ISO cooling energy efficiency ratio (EER) for the first and second units were 4.5 % higher and 3.9 % lower than the ARI EER, respectively. ISO heating capacity for the first and second units were 4.8 % lower and 2.9 % lower than the ARI capacity, respectively. ISO heating coefficient of performance (COP) for the first and second units were 6.2 % higher and 1.0 % lower than the ARI COP, respectively.