Method and apparatus for delivering conditioned air using pulse modulation

Apparatus for delivering conditioned air to a space, comprising:

• a source of conditioned air;
• a terminal unit communicating with said source to receive conditioned air therefrom and apply the air to the space, said terminal unit including a damper having a fully open condition wherein conditioned air is applied to the space by said terminal unit and a closed condition wherein the flow of conditioned air from said terminal unit is blocked by said damper;
• a sensor in the space sensing a selected condition therein;
• and
• a control system having sequential duty cycles each of a selected duration, said control system being responsive to the condition sensed by said sensor to effect the fully open condition of said damper for a selected time period during each duty cycle and the closed condition of said damper for the part of each duty cycle that does not include said selected time period.

Apparatus for delivering conditioned air to a space, comprising:

• a sensor for sensing a selected condition in the space;
• a plurality of terminal units each receiving conditioned air for application to the space, said terminal units being spaced apart in the space;
• a damper for each terminal unit having a fully open condition wherein conditioned air is applied to the space and a closed condition wherein the flow of conditioned air to the space is blocked, each damper having successive duty cycles each including a selected time period dependent on the condition sensed by said sensor;
• and
• a control system for effecting the fully open condition of each damper during said selected time period of each duty cycle and the closed condition of each damper during the part of each duty cycle that does not include said selected time period, said control system initiating the duty cycles of at least one damper at a different time than the duty cycles of another of said dampers is initiated.

Apparatus for delivering conditioned air to a room having a space located above a ceiling overlying the room, said apparatus comprising:

• a source of conditioned air;
• an enclosed supply plenum located in said space immediately above the ceiling and communicating with said source to receive conditioned air therefrom;
• a terminal unit on said ceiling arranged to receive conditioned air from said supply plenum and apply the conditioned air to the room;
• a temperature sensor in said room for sensing the air temperature therein;
• a damper associated with said terminal unit having a fully open condition wherein conditioned air is applied to the room by said terminal unit and a closed condition wherein the flow of conditioned air from said terminal unit is blocked, said damper having successive duty cycles each including a selected time period dependent on the temperature sensed by said sensor;
• a control system for effecting the fully open condition of said damper during said selected time period of each duty cycle and the closed condition of said damper during the part of each duty cycle that does not include said selected time period;
• a return air plenum in said space separated from said supply plenum and communicating with said source to supply return air thereto from the room;
• and
• a return register in the room communicating with said return air plenum to supply return air thereto.

An air terminal for applying conditioned air to a space, comprising:

• a housing presenting a flow path therethrough for the conditioned air;
• a damper for controlling flow through said path;
• a shaft on which said damper is carried, said shaft being mounted to said housing for movement between an open position of the damper wherein said flow path is open and a closed position of the damper wherein said flow path is closed;
• a magnet and a metal latch element cooperating to apply a magnetic force for releaseably latching said damper in the open position when moved thereto and in the closed position when moved thereto;
• and
• a power operated drive element connected with said shaft and arranged to overcome the magnetic force of said magnet and latch element to move the shaft between the open position and the closed position of said damper when power is applied to said drive element.

An air terminal for supplying conditioned air, comprising:

• a housing providing a flow path for accommodating passage of air therethrough;
• a baffle plate associated with said flow path and providing an outlet for discharging air from the flow path, said outlet varying in size with changes in the linear position of said plate;
• and
• an adjustable mount connecting said plate with said housing in a manner allowing linear adjustment of said plate to vary the size of said outlet.