Lochinvar Copper-Fin II CX401, Designer'S Manual, Page: 24 / 32

in the piping system as shown in Figure 22
should not restrict or vary the water flow
through the boiler. Constant water flow
through the boiler must be provided at all
times when the boiler is operating. The
boiler's operating temperature sensor can be
remote mounted in a bulb well installed in
the system water flow to control boiler
operation at a low temperature range. SPECIAL DESIGN
APPLICATIONS
Air Conditioning Re-Heat System
When used in connection with a refrigeration
system, the boiler
must be installed so the
chilled medium is piped in parallel with the
boiler and with appropriate valves to prevent
the chilled medium from entering the boiler.
The piping system of the hot water boiler
(when connected to heating coils located in
air handling units where they may be exposed
to refrigerated air circulation)
must be
equipped with flow control valves or other
automatic means to prevent gravity circulation
of the boiler water during the cooling cycle.
The heating coil
must be vented at the high
point, and the hot water from the boiler must
enter the coil at this point. Due to the fast
heating capacity of the boiler, it is not
necessary to provide a duct-stat to delay
circulator operation; also, omit thermal flow
checks, as the boiler is cold when the heating
thermostat is satisfied. This provides greater
economy overall by maintaining standby heat.
22
L o c h i n v a r
D E S I G N E R
’
S G U I D E C O P P E R
-
F I N I I B O I L E R
6 1 5 - 8 8 9 - 8 9 0 0
CAUTION!
For proper
operation the
system should
not be operated
at less than 12
PSIG.
EXPANSION
TANK
LOW WATER
FLOW SWITCH
PUMP
B
A
C
IN
R
OUT
WATER
SUPPLY
GAS
SUPPLY
DIAGRAM NOTES:
1. VALVES "D" AND "C" MAY BE MANUAL OR AUTOMATIC- TO SUIT.
2. PROVIDE DRAIN FOR RELIEF VALVE "R" TO SAFE PLACE.
3. CLOSE BOTH "A" AND "C" VALVES WHEN RUNNING CHILLER.
4. CLOSE BOTH "B" AND "D" VALVES WHEN RUNNING BOILER.
5. WATER SUPPLY VALVE REMAINS OPEN AT ALL TIMES.
D
E
HEATING &
COOLING
COIL
CHILLER
BOILER
(FIG. 24) HEATING/CHILLED WATER SYSTEM
Lochinvar
(FIG. 22) LOW TEMPERATURE BYPASS SYSTEM PIPING
ON/OFF FIRING ONLY
(FIG. 23) LOW TEMPERATURE BYPASS SYSTEM PIPING
PROPORTIONAL STAGED-FIRING