A minimum flow needs to be maintained in all closed circuit coolers to prevent potential freezing/bursting of the coil(s) during cold weather operation. Also, when the flow falls below a certain threshold it becomes laminar, which will significantly reduce performance during normal operation. The recommended minimum flow for each EVAPCO fluid cooler is located in its respective marketing product brochure. You can find all up-to-date materials in our comprehensive Document Library.
Regarding cold weather operation, the most foolproof method to prevent freezing is the use of ethylene or propylene glycol. Draining a coil should only be done in an emergency situation. Care must be taken to ensure that the piping is sized to allow the water to flow quickly from the coil. Coils should not be drained often, or for an extended period of time. Leaving the coil drained and open to the atmosphere can cause interior corrosion, which may lead to premature coil failure. Please contact your local EVAPCO sales representative or Mr. Goodtower® Service Center if you need additional assistance with winter operation/maintenance.