Chiller Load Calculator

2 air handlers × 55,000 CFM · 2 × 250-ton chillers · Qt = 4.5 × CFM × Δh

Inputs

Use live Dearborn data + operating schedule

Return-air temp (°F)

Return-air RH (%)

Below 55% lowers the discharge setpoint.

Fan speed (both air handlers) (%)

110,000 CFM total at 100%.

Outside-air temp (°F)

Outside-air RH (%)

Enthalpy computed from these.

Outside-air damper (% open)

100 = fully open

Return-air damper (% closed)

100 = fully closed

Discharge setpoint temp (°F)

Discharge RH (%)

Target enthalpy is derived from these.

—

tons

— BTU/hr

At the current airflow & mix. OA/RA ceilings assume the other stream stays where it is.