10
Application
Considerations
Open Loop System
Where an existing or proposed well can
provide an ample supply of suitable quality
water, ground water systems may be very
efficient. (See Figure 7)
Operation and benefits are similar to those
for closed loop systems. There are however
several considerations that should be
addressed prior to installation.
q
An acceptable way to discharge the
significant volume of used water from
the heat pump should be defined. It may
be necessary to install a recharge well to
return the water to the aquifer.
q
Water quality must be acceptable, with
minimal suspended solids. To help
ensure clean water, a straining device
may be required.
Figure 7: Open Loop system
Figure 8: Cooling tower/boiler system
Cooling Tower/Boiler System
A cooling tower/boiler system (see Figure 8)
utilizes a closed heat recovery loop along
with multiple water source heat pumps in a
more conventional manner.
Typically, a boiler is employed to maintain
closed loop temperatures above 60
F and a
cooling tower to maintain closed loop
temperature below 90
F. All the units
function independantly, either by adding
heat, or removing heat from the closed
water loop, making this system more
efficient than air cooled systems.
The cooling tower/boiler system provides a
low installation cost to the owner than other
systems. A good selection for large building
design needs.
