Air conditioning system

An air conditioning terminal operable to discharge conditioned air into an enclosed space, said terminal including means defining a plenum, means to provide a first conditioned air stream at a temperature which varies inversely to the temperature of the outdoor air to a first portion of said plenum, and means to provide a second conditioned air stream at a predetermined temperature level to a second portion of the plenum, said terminal further comprising:

• a. means to maintain said first air stream in said first portion of said plenum separate from said second air stream in said second portion of said plenum;
• and
• b. discharge means connected to said plenum to discharge the conditioned air into said space, said discharge means including first diffuser means to direct the first conditioned air stream along the ceiling of said space towards the peripheral wall thereof, said first air stream compensating for transmission gains or losses through said wall, and second diffuser means to direct the second conditioned air stream along the ceiling of said space towards the interior portion thereof, said second air stream compensating for the remaining cooling load in said space, the volume of said second air stream being varied in accordance with changes in said cooling load, the volume of said first air stream discharged into said space being maintained substantially constant irrespective of changes in the pressure of said air in said first portion of said plenum.