Pennant, 4a.4 freeze protection — boiler – LAARS Pennant PNCV (Sizes 500-2000) - Install and Operating Manual User Manual
Page 15

Pennant
(500-2000)
Page 15
PRIMARY/SECONDARY MANDITORY FOR ALL
VARIABLE FLOW SYSTEMS
INSTALL AIR VENTS AT HIGH POINTS IN SYSTEM
PIPING & SIZING OF EXPANSION TANK
PER TANK MANUFACTURER'S INSTRUCTIONS
DIMENSION "C" (COMMON PIPING) TO BE FOUR
PIPE DIAMETERS, MAX. (NO ELBOWS OR VALVES)
BOILER CIRCUIT PIPING MUST BE EQUAL
TO BOILER WATER CONNECTION SIZE
BOILER CIRC. PUMP SIZED FOR FLOW THROUGH BOILER
DOTTED DEVICES INDICATE ALTERNATE LOCATIONS
PUT BOILER CONTROL SENSOR IN THE SYSTEM
C
PUMP LOCATION FOR PUMP-MOUNTED UNITS
SYSTEM PUMP
MAKE-UP
COLD WATER
SUPPLY
SYSTEM
PUMP LOCATION FOR
NON-PUMP-MOUNTED UNITS
RETURN
SYSTEM
SUPPLY WHEN USING THIS PIPING STYLE.
MINIMUM BOILER INLET WATER TEMPERATURE
MUST BE AT LEAST 120°F.
C
LEGEND
CHECK VALVE
THERMOMETER
TEMPERATURE
SENSOR
GLOBE VALVE
EXPANSION TANK
WITH AIR SCOOP AND
AUTO AIR VENT
3-WAY VALVE
VALVE
CAUTION: THIS DRAWING SHOWS SUGGESTED
PIPING CONFIGURATION AND VALVING, CHECK
WITH LOCAL CODES AND ORDINANCES FOR
ADDITIONAL REQUIREMENTS.
PRESSURE REDUCING VALVE
W/ FAST FILL BYPASS
PURGE
VALVE
PUMP
Figure 4. Hydronic Piping — Multiple Boilers, Primary Secondary System.
4A.4 Freeze Protection — Boiler
Boiler installations are not recommended in
areas where the danger of freezing exists unless proper
precautions are made for freeze protection. A non
toxic, heating system, anti-freeze may be added to
the hydronic system provided that the concentration
does not exceed 50% and the anti freeze contains an
anti foamant. When a 50/50 mixture is used, increase
the water flow requirements by 15%, and increase the
headloss requirements by 20%.
Power outage, interruption of gas supply, failure
of system components, activation of safety devices,
etc., may prevent a boiler from firing. Any time a
boiler is subjected to freezing conditions, and the
boiler is not able to fire, and/or the water is not able
to circulate, there is a risk of freezing in the boiler
or in the pipes in the system. When water freezes,
it expands. This can result in bursting of pipes in the
system, or damage to the boiler, which could result in
leaking or flooding conditions.
IMPORTANT NOTES: Different glycol products
may provide varying degrees of protection. Glycol
products must be maintained properly in a heating
system, or they may become ineffective. Consult the
glycol specifications, or the glycol manufacturer, for
information about specific products, maintenance
of solutions, and set up according to your particular
conditions.