Closed Loop; Circulation System Design; Copper Water Coil Application; Figure 23 Circulation System - Bard QW Series Installation Instructions Manual

CLOSED LOOP

(Earth Coupled Ground Loop Applications)

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 or
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
NOTE: Apply petroleum
jelly to o-rings to prevent
damage and aid in insertion
Manual 2100-577C
Page 34 of 50
FIGURE 23
Circulation System
FLEXIBLE HOSE
PUMP MODULE
(See Spec Sheet
for Model No.)
WATER
OUT
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 Work sheet" section in manual
2100-099. Loop pump performance data can be seen
in Figures 25 and 26.

COPPER WATER COIL APPLICATION

Copper water coils are available as a factory-installed
option. The unit model number will indicate the coil
option as the next to last character; "C" represents
a water coil constructed of copper material and "N"
represents a water coil constructed of cupronickel.
The cupronickel coil is suitable for all applications.
The copper coil is suitable for applications using
ground loop and cooling tower only and is not
recommended for open well application.
PIPE FROM
GROUND LOOP
MIS-2748 A
PIPE TO
GROUND
LOOP