Greenheck ERCH - Energy Recovery Unit with Packaged DX (468151) - Manual (Page 11)

11
Energy Recovery Unit with Packaged DX
COIL APPLICATION RECOMMENDATIONS
Factory installed cooling and heating components are mounted
in the coil section of the unit . The coil section is downstream
of the energy wheel on the supply air side of the unit .
Note the coil connection locations on the picture . Coil
connections are located external to the unit as shown . Coil
connections that are not external have been ordered from the
factory with interior or exhaust airstream coil connections .
Note: DX coil liquid connection is internal to units .
WATER COILS
1 . Piping should be in accordance with accepted industry
standards . Pipework should be supported independently
of the coils . Water connections are male NPT iron pipe .
When installing couplings, do not apply undue stress to the
connection extending through the unit . Use a backup pipe wrench to avoid breaking the weld between coil
connection and header .
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 . To insure proper venting, an external air vent
in the piping is recommended . Connecting the supply and/or return in any other manner will result in very
poor performance . Be sure to replace factory installed grommets around coil connections if removed for
piping . Failure to replace grommets will result in water leakage into the unit and altered 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 40ºF; however,
the energy recovery wheel maintains a pre-coil temperature higher than 40ºF . 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 .
CONTINUOUS WATER CIRCULATION THROUGH THE COIL AT ALL TIMES IS HIGHLy RECOMMENDED .
5 . 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 6 feet per second and the friction loss should be approximately 3 feet
of water column per 100 feet of pipe .
DIRECT EXPANSION (DX) COILS WITH INTEGRAL CONDENSING SECTION
1 . The condensate drain pipe should be sized adequately to ensure the condensate drains properly . Refer to
Drain Trap section .
Hot
water coil
connections
Coil access door