What is chillerin construction?

An air-cooled chiller rejects heat directly to outdoor air through onboard condenser fans, so it is a packaged unit that sits outside on a pad or roof. A water-cooled chiller rejects heat to a condenser water loop, which means the estimate also has to carry a cooling tower, condenser water pumps, and a second piping system. Water-cooled plants are typically more efficient at larger tonnages, but the installed scope is substantially bigger than the chiller line alone.

One ton of refrigeration equals 12,000 Btu per hour of cooling, a unit left over from the days when cooling was delivered by melting ice (one ton of ice melting over 24 hours absorbs heat at roughly that rate). A 300 ton chiller can remove 3,600,000 Btu of heat per hour. Estimators use tons both to read the schedule and to benchmark installed cost per ton against past plant jobs.

The bare equipment price is the easy part. The misses are usually rigging and crane time, the concrete housekeeping pad, vibration isolation, flow switches and safeties, refrigerant monitoring in the machinery room, the chemical treatment tie-in, factory startup, and the scope boundary with the electrical contractor on the power feed. On some projects the owner buys the chiller directly, so confirm whether you are furnishing and installing or installing only.