cold weather operation will be enhanced if you read “Operating Cooling Towers in Freezing Weather” Marley Technical Report #H-003.
Ice forming characteristics on any given cooling tower will vary, depending on velocity and direction of wind, circulating water rate, and heat load. Excessive ice formation may be controlled by regulating air and water flow through the tower by one or more of the following procedures:
1–Shut the fan down. This reduces the cooling air rate to a minimum and increases the quantity of warm water at the air inlet to a maximum. However, normal “fan off” operation causes reverse air flow by aspira- tion and may cause water blowout and therefore must be done with caution and monitoring. For automatic operation, a timer switch can be provided to shut the fan down for a few minutes each hour.
2–When a cooling tower has two-speed motors, operate the fans at half speed forward. This reduces the cooling air rate (heat transfer) and increases the quantity of warm water at the air inlet.
3–With no heat load on the circulating water, icing cannot be controlled. Towers must not be operated with reduced water rate and/or no heat load during freezing weather. If a bypass directly into the cold water basin is used, all water must be bypassed.
Reverse operation of fans is not recommended . See “Fan Drive” for fan speed change precautions.
INTERMITTENT OPERATION–When the unit is operated intermittently during winter weather, it is necessary that the water be drained from the tower piping to insure protection against freezing and possible rupture.
Tower Maintenance
Always shut off electrical power to the tower fan motor prior to performing any inspections that may involve physical contact with the mechanical or electrical equipment in or on the tower. Lock out and tag out any electrical switches to prevent others from turning the power back on. Service personnel must wear proper personal protective clothing and equipment.
Well-maintained equipment gives the best operating results and the least maintenance cost. SPX recommends setting up a regular inspection schedule to insure effective, safe operation of the cooling tower. Use the schedule on page 16 to obtain continuously good performance with the
Caution
Warning