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
17
JE-Series
I s s u e D a t e :
M a y 1 0 , 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
Water-Loop Heat Pump Applications
Commercial Water Loop Applications
Commercial systems typically include a number of units
connected to a common piping system. Any unit plumbing
maintenance work can introduce air into the piping system;
therefore air elimination equipment is a major portion of the
mechanical room plumbing. Consideration should be given
to insulating the piping surfaces to avoid condensation.
Johnson Controls recommends unit insulation any time the
water temperature is expected to be below 60ºF (15.6ºC).
Metal to plastic threaded joints should never be used due to
their tendency to leak over time.
Teflon
®
tape thread sealant is recommended to minimize
internal fouling of the heat exchanger. Do not over tighten
connections and route piping so as not to interfere with
service or maintenance access. Hose kits are available from
Johnson Controls in different configurations for connection
between the unit and the piping system. Depending upon
selection, hose kits may include shut off valves, P/T plugs
for performance measurement, high pressure stainless
steel braided hose, “Y” type strainer with blow down valve,
auto-flow valve and swivel connections.
The piping system should be flushed to remove dirt, piping
chips, and other foreign material prior to operation (see
“Piping System Cleaning and Flushing Procedures” in
this manual). The flow rate is usually set between 2.25
and 3.5 gpm per ton [2.9 and 4.5 l/m per kW] of cooling
capacity. It’s recommended to use 3 gpm per ton [3.9 l/m
per kW] for most applications of water loop heat pumps.
To ensure proper maintenance and servicing, P/T ports are
imperative for temperature and flow verification, as well as
performance checks.
Water loop heat pump (cooling tower/boiler) systems
typically utilize a common loop, maintained between
60 - 90°F [16 - 32°C]. The use of a closed circuit
evaporative cooling tower with a secondary heat
exchanger between the tower and the water loop is
recommended. If an open type cooling tower is used
continuously, chemical treatment and filtering will be
necessary.
Typical Water-Loop Application
Unit Hanger Kits
(included)
Insulated supply duct with
at least one 90 deg. elbow
to reduce air noise
Suppy Air
Unit Power
Disconnect
Ball valve with optional
integral P/T plug
Unit Power
Power Wiring
Thermostat
Wiring
Stainless Steel
Braid Hose with
Integral “J” Swivel
3/8” [10mm] thread rods
(by others)
Building
Water out
Water in
Loop
Low Water Temperature Cutout Setting - DXM2 Control
When antifreeze is selected, the LT1 jumper (JW3) should
be clipped to select the low temperature (antifreeze 10.0°F
[-12.2°C]) setpoint and avoid nuisance faults (see “Low
Water Temperature Cutout Selection” in this manual).
Note: Low water temperature operation requires
extended range equipment.
