INSTALLATION AND OPERATION MANUAL
PAC HEAT RECOVERY WATER HEATER
If a water mixing valve is installed in the system, make sure that check valves are in both
hot and cold water lines. If this precaution is not taken, hot water may be drawn into the
cold water system under certain system operating conditions.
In many multi-unit installations, it is advantageous to install a circulating pump and form
a loop plumbing circuit through the Fre-Heaters. This will usually increase the heat
recovery efficiency of the system by keeping the total system water volume at a uniform
temperature and picking up the most available heat from any refrigeration units which may
be running. Consult a plumbing supply house for a hot water circulating pump suitable for
your particular installation. All pumps used in a Fre-Heater water circulation system must
be suitable for potable water use. . Multiple Fre-Heater installations may be piped in parallel if
care is taken to assure equal flow through all of the Fre-Heaters. Parallel plumbing is usually
reserved for installations having a common refrigeration compressor on all of the Fre-
Heaters. Refer to in the Figure.
Under certain circumstances, it may be necessary to operate a high temperature or
booster heater loop at temperatures above those attainable or desirable in the Fre-Heater. At
those times a piping scheme should be used. This allows the Fre-Heater to operate at its
optimum heat reclaim while the system temperature is at a higher level.
Figure 14 : Installing Water Piping
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