LAARS Heating Systems
Page 24
SECTION 5 Piping
5.A Boiler Water Piping
5.A.3 Freeze Protection
This unit may be installed indoors or outdoors. If
installing outdoors in a location that may experience
freezing temperatures, precautions must be taken to
prevent water in the heat exchanger and condensate
inside and outside of the boiler from freezing. Damage
due to freezing water or condensate is not covered by the
warranty.
If installed indoors, and there is an event such as a
power outage, interruption of gas supply, failure of
system components, activation of safety devices, etc.,
this may prevent a boiler from firing.
Any time a boiler
is subjected to freezing conditions, and the boiler
isnotabletofire,and/orthewaterisnotableto
circulate, there is a risk of freezing in the boiler
or in the pipes in the system.
When water freezes,
it expands. This may result in bursting of pipes, or
damage to the boiler, and this could result in leaking or
flooding conditions.
Do not use automotive antifreeze. To help prevent
freezing, The manufacturer recommends the use of
inhibited glycol concentrations between 20% and 35%
glycol. Typically, this concentration will serve as burst
protection for temperatures down to approximately
-5°F (-20°C). If temperatures are expected to be lower
than -5°F (-20°C), glycol concentrations up to 50% can
be used.
When concentrations greater than 35%
areused,waterflowratesmustbeincreasedto
maintain the desired temperature rise through the
boiler.
WARNING
Glycol must not be used in domestic hot water
applications. Refer to 5.B.4 on page 30 for
instructions on freeze protection for units (domestic
hot water).
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.
The following manufacturers offer glycols, inhibitors,
and anti foamants that are suitable for use in the unit.
Please refer to the manufacturers instructions for proper
selection and application.
• Sentinel Performance Solutions Group
5.A.1 Boiler Water Connections
NOTE: This unit must be installed in a closed
pressure system with a minimum of 12 psi (82.7 kPa)
static pressure at the boiler.
The water piping should be supported by suitable
hangers or floor stands. Do not support the piping with
this unit. The hangers used should allow for expansion
and contraction of pipe. Rigid hangers may transmit
noise through the system resulting from the piping
sliding in the hangers. We recommend that padding be
used when rigid hangers are installed. Maintain 1” (2.5
cm) clearance to combustibles for all hot water pipes.
Suggested piping diagrams are shown in Figure 8
through Figure 11. These diagrams are meant only as
guides. Components required by local codes must be
properly installed.
Thisunit’sefficiencyishigherwithlowerreturn
water temperatures.
Therefore, to get the best low
return temperature with multiple boilers, pipe as shown
in Figure 10 and Figure 11 on page 28.
Pipe the discharge of the relief valve (full size) to a drain
or in a manner to prevent injury in the event of pressure
relief. Install an air purger, air vent, expansion tank,
hydronic flow check valve in the system supply loop,
and any other devices required by local codes. The
minimum fill pressure must be 12 psig (82.7 kPa). Install
shutoff valves where required by code.
5.A.2 Cold Water Make-Up
1. Connect the cold water supply to the inlet
connection of an automatic fill valve.
2. Install a suitable back flow preventer between the
automatic fill valve and the cold water supply.
3. Install shut off valves where required.
In some installations, a hot water heating boiler is
connected to heating coils located in an air handling
unit where the coils may be exposed to refrigerated air
circulation. In these cases, the boiler piping system must
be equipped with flow control valves or other automatic
means to prevent gravity circulation of the boiler water
during the cooling cycle.
A boiler installed above radiation level, or as required by
the authority having jurisdiction, must be provided with a
low water cutoff device either as a part of the boiler or at
the time of boiler installation.
