Bard GSVS242-A, Installation Instructions Manual

Page: 18 / 39

Manual 2100-317J
Page
18 of 39
CLOSED LOOP
(EARTH COUPLED GROUND LOOP APPLICATIONS)
NOTE:
Unit shipped from factory with 27 PSIG low
pressure switch wired into control circuit and
must be rewired to 15 PSIG low pressure switch
for closed loop applications.
This unit is designed
to work on earth coupled ground loop systems,
however, these systems operate at entering water
(without antifreeze) temperature with pressures
well below the pressures normally experienced in
water well systems.
THE CIRCULATION SYSTEM DESIGN
Equipment room piping design is based on years of
experience with earth coupled heat pump systems. The
design eliminates most causes of system failure.
Surprisingly, the heat pump itself is rarely the cause.
Most problems occur because designers and installers
forget that a closed loop earth coupled heat pump
system is NOT like a household plumbing system.
Most household water systems have more than enough
water pressure either from the well pump of the
municipal water system to overcome the pressure of
head loss in 1/2 inch or 3/4 inch household plumbing. A
closed loop earth coupled heat pump system, however,
is separated from the pressure of the household supply
and relies on a small, low wattage pump to circulate the
water and antifreeze solution through the earth coupling,
heat pump and equipment room components.
The small circulator keeps the operating costs of the
system to a minimum. However, the performance of the
circulator MUST be closely matched with the pressure
of head loss of the entire system in order to provide the
required flow through the heat pump. Insufficient flow
through the heat exchanger is one of the most common
causes of system failure. Proper system piping design
and circulator selection will eliminate this problem
Bard supplies a work sheet to simplify head loss
calculations and circulator selection. Refer to
“Circulating Pump Worksheet” section in manual
2100-099.
FIGURE 6
CIRCULATION SYSTEM DESIGN
1" FLEXIBLE HOSE
WATER OUT
OPTIONAL VISUAL
FLOW METER
NOTE: IF USED
SUPPORT WITH A
FIELD-FABRICATED
WALL BRACKET
HOSE CLAMPS
WATER
IN
PUMP
MODULE
PIPE FROM
GROUND LOOP
PIPE TO GROUND LOOP
BARB X INSERT
BRASS ADAPTERS