JRC-Series
R e v. : D e c e m b e r 8 , 2 0 2 1
T H E S M A R T S O L U T I O N F O R E N E R G Y E F F I C I E N C Y
I n s t a l l a t i o n , O p e r a t i o n , M a i n t e n a n c e
15
Ground-Water Heat Pump Applications, Cont’d.
Notice! Ground-water applications for commercial
buildings with more than 2-3 units should include a
plate frame heat-exchanger to isolate the heat pumps
from the ground-water and confine heat exchanger
cleanings to one location and lessen maintenance.
Direct use of ground-water may increase the
frequency of heat pump maintenance and may
shorten life expectancy.
Flow Regulation -
Flow regulation can be accomplished
by two methods. One method of flow regulation involves
simply adjusting the ball valve or water control valve on the
discharge line. Measure the pressure drop through the unit
heat exchanger, and determine flow rate. Since the pressure
is constantly varying, two pressure gauges may be needed.
Adjust the valve until the desired flow of 1.5 to 2 gpm per
ton [2.0 to 2.6 l/m per kW] is achieved. A second method
of flow control requires a flow control device mounted on
the outlet of the water control valve. The device is typically
a brass fitting with an orifice of rubber or plastic material
that is designed to allow a specified flow rate. On occasion,
flow control devices may produce velocity noise that can be
reduced by applying some back pressure from the ball valve
located on the discharge line. Slightly closing the valve will
spread the pressure drop over both devices, lessening the
velocity noise.
Note: When EWT is below 50°F [10°C], 2
gpm per ton (2.6 l/m per kW) is required.
Water Coil Low Temperature Limit Setting -
For all open
loop systems the 30°F [-1.1°C] LT1 setting (factory setting-
water) should be used to avoid freeze damage to the unit.
See “Low Water Temperature Cutout Selection” in this
manual for details on the low limit setting.
