Ceiling construction for a heating, ventilation and air conditioning system

Claim 1

In a building having a heating, ventilation and air conditioning system, exterior walls and at least one story having a true ceiling, a suspended ceiling, and lighting fixtures occupying openings in the suspended ceiling, the true and suspended ceilings being vertically spaced thereby to form a plenum, the improvement comprising means partitioning the plenum into an interior plenum forming a return air plenum for said system and at least one perimeter plenum, the exterior walls forming the periphery of each said at least one perimeter plenum and each said at least one perimeter plenum surrounding said return air plenum and being in non-communicating relation with said return air plenum, temperature sensing means located outside said building and temperature sensing means located within said perimeter plenum, ventilation control means operatively connected to the perimeter plenum to control the ventilation of said perimeter plenum wherein said ventilation control means is regulated by a scheduled control unit that is operatively connected and responsive to the temperature sensing means located within said perimeter plenum and temperature sensing means located outside said building, said scheduled control unit being arranged to change the perimeter plenum temperature by regulating said ventilation control means in response to changes in the sensed temperature outside the building and thereby regulate the radiant heat transfer from the perimeter plenum to the space below the suspended ceiling, the suspended ceiling allowing the passage of air between the space below the suspended ceiling and the plenums.