Kees MUA TEMPERED MAKE-UP AIR UNITS - Heating & Cooling Coil I & M Manual - Manual (Page 3)

KEES, INC.
Products for Food Service & Sheet Metal Industry
400 S. INDUSTRIAL DRIVE - P.O. BOX L - ELKHART LAKE, WISCONSIN 53020 - (920) 876-3391 - FAX (920) 876-3065
Water Coil Instructions
Application Recommendations:
1. Piping should be in accordance with accepted industry standards.
2. Connect the WATER SUPPLY TO THE BOTTOM CONNECTION on the air leaving side and the
WATER RETURN TO THE TOP CONNECTION on the air entering side. The extra bottom
connection can be used for an auxiliary manual drain connection, and the extra top connection can
be used for an automatic air vent or the extra connections can be capped. Connecting the supply
and/or return in any other manner will result in very poor performance.
3. The air vent at the uppermost point should be temporarily opened during system start-up to release
all of the air from the coil. To maintain heat transfer capacity, periodically vent any air in coil.
4. Water coils are not normally recommended for use with entering air temperatures below 40F;
however, special high-pressure water coils have been used successfully on high temperature hot
water jobs with low entering air temperatures when correctly controlled. No control system can be
depended on to be 100% safe against freeze-up with water coils. Glycol solutions or brines are the
only safe media for operation of water coils with low entering air conditions.
5. When fresh and return air are to be heated by hot water coil, care should be used in the design of the
duct work to ensure thorough mixing before the air enters the coil. The return air should always enter
the bottom of the duct and fresh air should enter the top of the duct. The greater the distance
between the mixing point and the entrance to the coil, the better the application. Temperature control
elements should be located to sense the lowest temperature air that will enter the coil. Always install
gasketed fresh air dampers which are automatically controlled to close whenever the water leaving
the coil is too cool, or the fan stops. Care should be used in designing fresh air intake to prevent
stack effect (or wind) from forcing cold air through the coils when the fan is shut down. Two sets of
dampers are frequently required. CONTINUOUS WATER CIRCULATION THROUGH THE COIL AT
ALL TIMES IS HIGHLY RECOMMENDED.
6. Pipe sizes for the system must be selected on the basis of the head (pressure) available from the
circulation pump. The velocity should not exceed 8 feet per second and the friction loss should be
approximately 3 feet of water column per 100 feet of pipe.
7. For chilled water coils, the condensate drain pipe should be sized adequately to ensure the
condensate drains properly.