In Wisconsin, an improperly winterized cooling tower or chiller can mean cracked basins, split coils, frozen piping, and a costly spring startup. As cooling season winds down, facilities that don't require year-round cooling need a deliberate shutdown plan – and facilities that do run through winter need freeze protection in place before the first hard frost.
At BREDAN Mechanical Systems, we help commercial and industrial clients across Southeast Wisconsin winterize cooling towers, chillers, and chilled water systems every fall. Here is what a proper shutdown involves.
Cooling Tower Winterization
Drain and Clean
- Drain the cold water basin, distribution pans, and exposed piping
- Remove scale, sludge, and biological growth from the basin and fill media
- Flush strainers and clean basin screens
- Inspect fill, drift eliminators, and louvers for damage
Mechanical Components
- Inspect fan blades, shafts, and gearboxes
- Change gearbox oil and lubricate bearings per manufacturer guidance
- Check belt condition and tension on belt-driven units
- Lock out fan motors to prevent accidental operation
Freeze Protection
- Verify basin heaters operate (for towers that stay wet)
- Confirm heat trace on makeup water lines and exposed piping
- Leave drains open where appropriate to prevent water accumulation
Year-Round Towers
Many manufacturing plants, data rooms, and hospitals need cooling all winter. For these systems, winterization focuses on freeze prevention rather than shutdown: verifying basin heaters, setting fan cycling and bypass valves to maintain minimum water temperatures, and confirming that controls will respond correctly during sub-zero conditions.
Chiller Shutdown
Water-Cooled Chillers
- Drain condenser water from the chiller barrel if the space is unheated
- Inspect and clean condenser tubes – fall is the ideal time for tube brushing
- Perform eddy current testing on tubes when due
- Record refrigerant pressures and operating data for comparison at spring startup
Air-Cooled Chillers
- Verify glycol concentration provides adequate freeze protection
- Drain evaporators that are not glycol protected
- Clean condenser coils and inspect fan motors
- Confirm crankcase heaters are energized
Chilled Water Piping and Coils
Freeze damage often occurs in air handler coils, not the chiller itself. Outdoor air dampers that fail open on a cold night can freeze and split a chilled water coil in hours. As part of winterization, we:
- Test freeze stats and low-limit controls on air handlers
- Verify outdoor air dampers close on unit shutdown
- Drain or glycol-protect coils in units exposed to outdoor air
- Check glycol concentrations with a refractometer
Documentation for Spring Startup
A well-documented fall shutdown makes spring startup faster and less expensive. We provide clients with a report covering equipment condition, recommended repairs, and parts to order over the winter – so cooling systems are ready the moment warm weather returns.
Cooling Tower & Chiller Service in Southeast Wisconsin
BREDAN Mechanical Systems provides cooling tower service, chilled water system maintenance, and chiller winterization for facilities throughout Waukesha, Milwaukee, Kenosha, Racine, Washington, Ozaukee, and Jefferson counties. Contact our team to schedule your fall shutdown before freezing temperatures arrive.
