Cooling Tower Winterization
With the winter season fast approaching, it’s imperative that the cooling tower be in an appropriate condition for sub-zero operation. Prior to every winter season, it’s prudent to check the following areas of your cooling tower:
- Structure & Seams
- Basin heater
- Low water cut out
- Mechanical assembly
Structure & Seams
Leaks are unfortunately a common issue with older cooling towers. After many years of operation, the caulking and sealer material dries out, galvanized steel panels rust and develop pinholes, and spray system joints and distribution nozzles can fail (or become clogged) and cause condenser water to exit the box.
During summer operation, leaks are limited to being a costly annoyance, as the tower make up water will engage more often and send city water into the loop to compensate, but in winter operation, leaks can often mean major structural damage to both the cooling tower and surrounding areas.
Sometimes a cooling tower may not even be presenting leaks during warmer weather operation, but because of balancing issues at the upper hot deck, water that would have otherwise made its way back to the tower interior flash freezes along the louver face.
Winter operation leaks (when left unattended to) build, and build, into an ever-growing stalagmite of ice.
Basin Heater & Low Water Cut Out
Prior to the winter operation season, it’s imperative that electrical testing be performed on all winter operation components, including the basin heater, and heat trace. The basin heater thermostat must also be tested to ensure functionality, so that in the event of a sudden drop in basin temperature, the heater element will engage to keep the basin from freezing. In the event the heater element fails to engage, and temperatures drop, the cooling tower basin will freeze solid, restricting water back to the building system on startup.
The cooling tower is also equipped with a low water cut out switch, positioned above the heater element. In the event the water level suddenly, and unexpectedly, drops below this safety switch, it will cut power to the heater element. This switch should be tested prior to winter operation to avoid a costly heater failure in the event of sudden water loss.
Many cooling towers operate with a centrifugal fan (blower wheel) arrangement, which utilizes fan snouts within a pressurized box. Over time, these fan snouts can develop holes from metal corrosion. When the fans cycle off, water will infiltrate the interior snout and escape back through the blower wheel and onto the rotating components (shaft & bearings). In extreme cold weather conditions, this infiltration can cause serious damage to the rotating machinery upon startup.
It is always prudent to review the condition of the cooling tower winter operation components, and ensure that any leaking sections are addressed prior to colder weather seasons. For more information on winterization packages, winter operation components, or for a comprehensive review of your cooling tower, call Cooling Tower Maintenance (CTM) today at 1-800-311-1200.