Water Source Heat Pump System Operation
Figure 2: Typical Water Source Heat Pump System Diagram
Water Source Heat Pump System
The water source heat pump system is, by definition, a heat recovery
system. It is best applied to buildings that have simultaneous cooling
and heating loads. This is the case during winter months when the
interior zones of a typical building require cooling while the exterior
zones require heating. When a water source heat pump system is used,
the heat rejected by the cooling units is used to warm the zones calling
for heat. A water heater or boiler is generally used for adding heat to the
condensing water during peak heating periods, if necessary. The system
also utilizes a water cooling tower to reject the heat energy from the
condenser water loop during periods of high cooling demand.
Water source heat pump units can be suspended in the ceiling plenum,
floor mounted behind walls or placed directly in the occupied space as
a console unit. There are also rooftop and unit ventilator type water
source heat pumps.
Water source heat pump systems generally cost less to install than central
built-up systems. They offer individual zone control with the added
flexibility of being able to accommodate changes in location and sizes as
thermal zones or zone occupancy change. This system is often installed
in ceiling plenums, which frees up valuable floor space.
Another valuable benefit of water source heat pumps is that they can
accommodate simultaneous calls from zones requiring heating or
cooling. Depending on the climate, outside air may require preheat or
cooling prior to being introduced to the unit. In the example of ceiling
mounted water source heat pumps, put outside air ducts near each unit
to improve indoor air quality.
Normally, multiple units serve an occupied space. This gives component
redundancy to the system so if one unit were to fail, the other units could
back it up until the unit was repaired. The packaged design of most unit
types allows quick change-out by service personnel so maintenance can
typically be performed off site.
As with any HVAC system, there is a negative side as the water source
heat pump system often requires higher maintenance costs than conven-
tional air side systems. The system also typically has a shorter replace-
ment life than other systems because of continuous fan and compressor
operation during heating and cooling modes. The system can also create
room noise since the compressor and fan are commonly located close
to the zone occupant. Placing units away from the occupied space and
ducting the supply air to the zone can minimize potential noise problems.
General Information
5
WSHP Loop Controller
GPC-XP Guide
