Install Instructions

IOM - HZH/HZV Series
17
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. Comfort-Aire/
Century 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 Comfort-Aire/Century 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, and/or “J” type
swivel connection.
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. Comfort-Aire/Century
recommends 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 on 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.