What capacity is to be used for centrifugal chillers that, due to their selection conditions, cannot operate at AHRI standard conditions?
The AHRI flow rates are based on capacity. This leads to circular calculation since AHRI standard conditions are dependent on capacity, but capacity is the desired output. How does the project team resolve this circular calculation?
To determine the Gross AHRI rated cooling capacity (tons) of an individual HVAC or refrigeration unit that cannot operate at AHRI standard conditions, use the design and selected conditions of the equipment drawing or schedule. Enter this cooling capacity in the Qunit (tons) column in Table. Mechanical and Cooling and Refrigeration Equipment in the credit form.
To determine unit capacity in tons for centrifugal chillers that cannot operate at AHRI standard conditions, use selected flow rates for the evaporator, and use standard AHRI temperatures established for the individual HVAC or refrigeration unit.