LAARS Mascot LX MLXC 175 MBH - Install and Operating Manual - Manual (Page 23)

Mascot LX Boilers and Water Heaters Page 19
NOTE: Laars supplied pumps are not all capable of
maintaining the reduced temperature rise required
with glycol concentrations greater than 35%.
NOTICE
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.
6.4 Recognized Chemicals
The following manufacturers offer glycols, inhibitors,
and anti-foamants that are suitable for use in the Mascot
LX. Please refer to the manufacturers instructions for
proper selection and application.
1.
Sentinel Performance Solutions Group
2. Hercules Chemical Company
3. Dow Chemical Company
6.5 Domestic Hot Water Piping (MLXC)
Connect domestic hot and cold water piping to the
boiler at locations noted in Figure 14 . Expected DHW
performance is indicated in Table 13 .
Use of flow restrictor is optional to prevent colder water
at excessive flow rates. Contact Laars for alternate
configurations.
6.6 Indirect Water Heater Piping
The MLXH model can control an indirect water heater
zone. Pipe to the locations shown in Figure 14 . Setpoint
is made via aquastat or sensor well located on the
indirect water heater, or can be controlled at the boiler
via a remote sensor. See Section 9 for control details.
Sensor, Laars PN E2337501
Mascot LX's efficiency is higher with lower return
water temperatures.
Laars strongly recommends that Mascot LX be piped
in a primary-secondary fashion (using either piping or a
hydraulic separator) such that the pump that is mounted
on the boiler ONLY serves the boiler.
Mascot LX boiler must be located within 15 feet
(4.6m) of the supply and return header (or the hydraulic
separator). The pump is sized for a maximum of 30 feet
(9.1m) of piping and the headloss of the boiler only.
The system designer should take into account allowable
boiler temperature rise of 65°F (36°C) Maximum.
6.2 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.
The boiler piping system of a hot water heating boiler
connected to heating coils located in air handling
appliances 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.
A boiler installed above radiation level, or as required
by the authority having jurisdiction, must be provided
with a low water cutoff device at the time of boiler
installation.
6.3 Freeze Protection
Mascot LX units are certified for indoor use only, and
are not design-certified for placement outdoors.
Proper precautions for freeze protection are
recommended for boiler installations in areas where the
danger of freezing exists.
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 which
may result in bursting of pipes, or damage to the boiler,
which could result in leaking or flooding conditions.
Do not use automotive antifreeze or ethylene glycol.
To help prevent freezing, Laars recommends the use
of inhibited propylene 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.