Kees MUA TEMPERED MAKE-UP AIR UNITS - Heating & Cooling Coil I & M Manual - Manual (Page 4)

Water Coil Instructions
(continued)
Maintenance Instructions:
1. Filters upstream of the coil should be checked regularly for dirtiness and clogging. If the filters are
dirty, they should be cleaned or replaced. It is important that the coils stay clean to maintain
maximum heat transfer capability.
2. Coils must be clean to obtain maximum performance. Check once a year under normal operating
conditions and, if dirty, brush or vacuum clean. Soiled fins reduce the capacity of the coil, demand
more energy from the fan, and create an environment for odor and bacteria to grow and spread
through the conditioned zone. High pressure water (700 Psi or less) may be used to clean coils with
fin thickness over 0.0095 inches thick. TEST THE SPRAY PRESSURE over a small corner of the coil
to determine if the fins will withstand the spray pressure.
For coils with fragile fins or high fin density, foaming chemical sprays and washes are available. Many
coil cleaners contain harsh chemicals, so they must be used with caution by qualified personnel only.
Care must be taken not to damage the coils, including fins, while cleaning. CAUTION: Fin edges
are sharp.
3. Drain pans in any air conditioning unit will have some moisture in them, therefore, algae and other
organisms will grow due to airborne spores and bacteria. Periodic cleaning is necessary to prevent
this build-up from plugging the drain and causing the drain pan to overflow. Inspect twice a year to
avoid the possibility of overflow. Also, drain pans should be kept clean to prevent the spread of
disease. Qualified personnel should perform cleaning.
Winterizing Coils:
1. Coils freeze-up can be caused by such things as air stratification and failure of outdoor air dampers
and/or preheat coils. Routine draining of water cooling coils for winter shutdown cannot be depended
upon as insurance against freeze-up. Severe coil damage may result. It is recommended that all coils
be drained as thoroughly as possible and then treated in the following manner.
2. Fill each coil independently with an antifreeze solution using a small circulating pump and again
thoroughly drain. Check freezing point of antifreeze before proceeding to next coil. Due to a small
amount of water always remaining in each coil, there will be diluting effect. The small amount of
antifreeze solution remaining in the coil must always be concentrated enough to prevent freeze-up.
3. NOTE: Carefully read instructions for mixing antifreeze solution used. Some products will have a
higher freezing point in their natural state than when mixed with water.