College Park, MD
of piping are exposed to weather, where heating
considered in lieu of convective or all-air heating systems
operations are intermittent or where coils are exposed to
in areas that experience infiltration loads in excess of two
large volumes of outdoor air. Freeze protection circulation
air changes per hour at design heating conditions. Radiant
pump shall be provided along with polypropylene glycol.
heating systems may also be considered for high bay
Heat tracing systems are not acceptable for systems inside
spaces and loading docks.
the building. Glycol solutions shall not be used directly
Natural Gas Piping. Refer to Plumbing Systems, Natural
in boilers, because of corrosion caused by the chemical
Gas Systems section of this chapter.
breakdown of the glycol. The water make-up line for
glycol systems shall be provided with an in-line water
Fuel Oil Piping. Refer to Plumbing Systems, Fuel Oil
meter to monitor and maintain the proper percentage of
Systems section of this chapter.
glycol in the system. Provisions shall be made for drain
down, storage and re-injection of the glycol into the
Underground Fuel Oil. Refer to Plumbing Systems, Fuel
Oil Systems section of this chapter.
Radiant heating systems (hot water
fired) may be overhead or underfloor type. They may be
Primary Heating Systems
Revised March 2005 PBS-P100