AIR CONDITIONING AND VENTILATING SYSTEMS

AIR CONDITIONING SYSTEMS ARE A FORM OF MECHANICAL REFRIGERATION.  A GAS, SUCH AS FREON, IS COMPRESSED IN COILS INTO A LIQUID, THEN ALLOWED TO EXPAND BACK INTO A GAS.  DURING EXPANSION, FREON COOLS.

AIR CONDITIONING SYSTEMS HAVE THREE MAJOR COMPONENTS:  AIR-INTAKE SYSTEMS, CONDITIONING EQUIPMENT AND A DISTRIBUTION SYSTEM.

IN GENERAL, THE REFRIGERANT POSES A TOXICITY PROBLEM AND SOMETIMES A COMBUSTIBILITY / FLAMMABILITY HAZARD.  THE GREATEST PROBLEM, HOWEVER, IS THE EXPLOSION HAZARD DUE TO THE PRESSURIZATION OF THE REFRIGERANT.

CONDITIONING EQUIPMENT (HVAC), INCLUDING AIR HEATING AND COOLING UNITS SHOULD BE PROTECTED IN A ROOM DESIGNATED WITH A 1 HOUR FIRE RATING.

DISTRIBUTION EQUIPMENT (DUCT WORK) CAN PROVIDE A MEANS FOR SMOKE, GASES, HEAT AND FLAME TO SPREAD THROUGHOUT THE ENTIRE AREA SERVED BY THE DUCT SYSTEM.

PROVISIONS MUST BE MADE TO CONTROL THE SMOKE WITHIN THE BUILDING.  MOST BUILDINGS USE A SYSTEM OF PASSIVE SMOKE CONTROL; THE COMPARTMENTALIZING CONCEPT IS USED.  FANS SHOUT DOWN, AND FIRE AND SMOKE DAMPERS CLOSE TO PREVENT THE FURTHER SPREAD OF FIRE AND SMOKE.

THE ACTIVE APPROACH MAY USE THE BUILDING HVAC SYSTEM TO CREATE AND MAINTAIN DIFFERENTIAL PRESSURE THAT PREVENTS SMOKE FROM MOVING FROM ONE STRUCTURE TO ANOTHER AND EXHAUST COMBUSTION PRODUCTS FROM THE STRUCTURE.

MAINTENANCE AND INSPECTION

• A SCHEDULE FOR MAINTENANCE AND CLEANING IS THE KEY TO A SAFE HVAC OPERATION.

HVAC INSPECTION SHOULD INCLUDE:

1. FILTERS EXAMINED FOR CLEANLINESS AND SUITABILITY.
2. MOTORS AND FANS SHOULD BE FREE FROM DUST, OIL AND DIRT ACCUMULATIONS.
3. GAS BURNERS SHOULD BE PROPERLY ADJUSTED.
4. AIR SUPPLY FOR BURNER COMBUSTION MUST BE ADEQUATE.
5. FILTERS AND DUCTS SHOULD BE CLEANED AND MAINTAINED UNOBSTRUCTED.

       
INDEX Heating Systems

FPT 102 - Fire Prevention and Inspection // Instructor: Kevin M. Kolb        Slide #5