4 Cold Weather Operations
4 Cold Weather Operations
W W W . B A L T I M O R E A I R C O I L . E U
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COLD WEATHER OPERATIONS
About cold weather operation
BAC cooling equipment can be operated in sub freezing ambient conditions provided the proper measures are
taken. Listed below are general guidelines which should be followed to minimize the possibility of coil freeze-up.
As these guidelines may not include all aspects of the anticipated operation scheme, system designer and
operator must thoroughly review the system, location of the equipment, controls and accessories to ensure reliable
operation at all times.
Protection against sump water freezing
To prevent sump water from freezing, either sump heaters or a remote sump located in a heated indoor area must
be installed. For a seasonal shut down during the cold weather period, it is recommended to drain the sump and
pump.
Drainage of the sump and pump will also be needed if dry operation is anticipated, even if sump heaters are
installed. These heaters will NOT prevent sump water from freezing during dry operation at sub freezing ambient
conditions. Remote sump installations are best suited for a flexible switch from wet to dry operation, as the sump
water is protected at all times. For dry operation applications, ensure that make-up water line is shut off and make-
up valve completely drained.
Thermostats for electrical sump heaters for this equipment are set to maintain a sump water temperature of 4°C.
CAUTION
Switch off heaters when the sump is drained.
Capacity control
In addition to protecting the sump water, all exposed water piping, in particular make-up water lines should be heat
traced and insulated.
Spray pumps also need to be heat traced and insulated from pump suction to the overflow level, if they can be
exposed to sub-freezing ambient conditions.
It is necessary to prevent the recirculating water from approaching freezing conditions when the system is
operating under load. The most « critical » situation occurs, if operation at subfreezing conditions coincides with
light load conditions. The key to protecting the recirculating water is capacity control by adjustment of air flow to
maintain the temperature of the recirculating water minimal above freezing point. As a rule of thumb this minimum
temperature is 5°C, but there are applications, where even lower temperatures can be accepted. (Contact your
local BAC Balticare representative for advice.)
VCL
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