Underground parking lots may utilize
a ramp heating system to prevent adherence of snow and ice during the winter
months. The most prevalent type is the hot water heating glycol system.
These are recirculating hot water heating systems piped beneath the concrete
ramps, designed to generate radiant heat to the ramps. These heating
systems utilize a tube in shell heat exchanger, deriving heat from a main
heating system. A separate recirculation pump is used. Glycol is added
to the ramp heating system to provide freeze or burst protection to the
piping coils beneath the ramp. Depending upon the exposure, severity of
local winter conditions, historical amounts of snow and ice, the glycol
percentage is adjusted up to 50 percent glycol / water ratio.
These system experience similar problems to
those of larger glycol systems: breakdown of glycol and system fluid loss.
The glycol should be checked on a yearly basis to ensure adequate freeze
protection, inhibitor level and pH. Sufficient reservoir glycol / water
in the expansion tank should also be verified.
Older systems that have not been properly
inhibited or maintained may be affected by oxides of corrosion by products,
glycol sludging and inhibitor depletion. Caution should be observed to
ensure the compatability of inhibitor packages from glycol source to source.
Clean up procedures may include the flushing
of the system, replenishment of the glycol, and chemical cleaning of the
heat exchanger, if necessary.
