Rev.01 03-27-17
Page 15 of 67
Compu-Aire
3.7
Water Cooled Energy Miser
Summary of Equipment
Energy miser units are provided with Dual Cooling options. DX cooling using Compressor based
system and Economizer cooling using Water Side Economizer Coil.
The primary system shall be Direct Expansion Cooling. The free cooling Energy miser coil is
provided together with the DX cooling coil. If the Water temperature drops below the Energy
miser set point, the condenser water is diverted to the free cooling coil and DX cooling will be
programmed to either turned off or made available to assist based on demand.
The Energy miser System shall come standard with a three (3) way water regulating valve for
condenser coil, a three (3) way modulating chilled water valve for energy miser coil, DX coil(s),
compressor(s) and co-axial water condenser(s). The water valves on water cooled condensers and
free cooling energy miser CW Valves are Three Way mixing type designed to divert the flow in
either condenser coil or free cooling EM coil. Three (3) way is used to maintain pressure drop, as
constant GPM is required for free cooling systems. The (3) three way control valve shall control
the amount of flow to auxiliary energy miser cooling coils and maintain constant temperature and
relative humidity
Energy miser systems are connected to Cooling Tower or Dry Fluid Coolers to obtain re-circulating
water or water glycol solution. In addition, the system is equipped with steam generating
humidifier, electric reheat and microprocessor based controller.
A unique feature of Energy miser system is that the free cooling water coil is located just before
the direct expansion coil and is properly sized to provide the same cooling capacity as the DX
system at 45°F entering water temperature.
Cooling-Direct Expansion
Direct Expansion Cooling shall operate when the water temperature increases above the specified
set point. A digital signal is sent to the system by microprocessor to signal the three (3) way valve
to divert the water flow from the free cooling coil to the water cooled condensers and the direct
expansion cooling mode shall start. The microprocessor shall signal the compressor to start
cooling and at the same time energize the water regulating valve to supply water flow to the co-
axial condenser. The Energy miser mode depends on the entering water temperature and it is
adjustable.
Note:
Continuous water shall be flowing through the chilled water valve and will only supply
water to coil when called upon.
