Intertek FT Series - Freeze Protection

The FT Series Floor Standing, Heating Only Boiler
Page 81
8.2 Freeze Protection
FT Boilers are certied for indoor use only, and are not
design-certied 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 ring. Any time a boiler
is subjected to freezing conditions, and the boiler
is not able to re, 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
ooding conditions.
NOTICE
Not all pumps are capable of maintaining the
reduced temperature rise required with glycol
concentrations greater than 35%.
NOTICE
Di󰀨erent glycol products may provide varying
degrees of protection. Glycol products must
be maintained properly in a heating system, or
they may become ine󰀨ective. Consult the glycol
specications, or the glycol manufacturer, for
information about specic products, maintenance
of solutions, and set up according to your particular
conditions.
Some items to consider are
• Consider the e󰀨ects of reduced heat transfer and
an increase in head pressure against the system
circulator. For example: A 30% mixture of glycol will
result in a BTU output loss of 15% with a 5% increase
in head against the system circulator.
• Glycol mixtures should not exceed 40%. A 50%
mixture of glycol will result in a BTU output loss of
30% with a 50% increase in head against the system
circulator. Glycol concentrations above 40% by
volume can lead to short cycling of the burner.
• The glycol solution should be tested as
recommended by the glycol manufacturer but not
less than annually. Some items of concern are pH
additive breakdown, inhibitor reduction, etc.
• Glycol/antifreeze solutions expand more than water;
therefore, system design must take this into account.
For example: a 40% by volume solution expands
4.8% in volume for a temperature increase from 32◦F
to 180◦F, while water expands 3% over the same
temperature rise.
CAUTION
It is highly recommended to follow the manufacturers
recommended concentrations, expansion requirements,
and maintenance recommendations. You must carefully
calculate the additional friction loss in the system as
well as the reduction in the heat transfer coe󰀩cients.
__________________________________________
NOTICE
Do not exceed a 40% glycol concentration by volume
as it may result in short cycling of the burner.
WARNING
Do NOT use automotive antifreeze or
ethylene glycol. Use only inhibited propylene
glycol solutions which are specially
formulated for hydronic systems. Ethylene
glycol is toxic and can attack gaskets, seals,
and metallic components used in hydronic
systems. A correct glycol concentration and
inhibitor level is critical.