AIR CONDITIONING SYSTEM WITH VARIABLE PRIMARY AIR VOLUME TERMINAL AND METHOD OF OPERATION THEREFOR

• US 3,720,258 A
• Filed: 07/14/1970
• Issued: 03/13/1973
• Est. Priority Date: 07/14/1970
• Status: Expired due to Term

• Current Assignee: Robert B. Chandler
• Original Assignee: Robert B. Chandler
• Inventors: Chandler, Robert B.
• Primary Examiner(s): Davis, Jr., Albert W.
• Application Number:
  US05/054,782
• Time in Patent Office: 973 Days
• Field of Search: 165/123,22,16 98/4DL,38E 236/13,49
• US Class Current: 165/213
• CPC Class Codes: F24F 2221/02 combined with lighting fixtures
• CPC Class Codes: F24F 2221/14 mounted on the ceiling
• CPC Class Codes: F24F 3/048 with temperature control at constant rate of air-flow

Abstract

An air conditioning system and method of operating an air conditioning system wherein conditioned primary air is transmitted to a plenum chamber in a terminal unit, which terminal unit may be positioned for example, directly within a space to be conditioned or supported above a suspended ceiling in a space to be conditioned. A portion of the primary air is utilized to pass through nozzles and establish primary air flow in a mixing duct, which flow may induce and mix with a flow of secondary air to constitute supply air for discharge into a space to be conditioned. The supply air may comprise solely primary air or selectively variable volumes of primary air and secondary air, which secondary air may include selectively variable volumes of air recirculated from the space being conditioned and, if appropriate, air from the plenum chamber formed by a suspended ceiling in the space to be conditioned. Additionally, an air handling or terminal unit according to the invention may include a casing connected to a source of primary air for providing a constant flow of primary air and a selectively variable flow of primary air, means for selectively introducing and mixing a flow of secondary air with the constant flow of primary air, the secondary air comprising selectively volumes of recirculated air from the space and, if appropriate, volumes of air drawn from the plenum chamber defined by a suspended ceiling in the space to be conditioned and a control means for controlling the thermal capacity of supply air for the space, the supply air including the primary air from the constant flow and, selectively, volumes of additional or by-pass primary air and secondary air.

Claims

1. An air conditioning system for controlling the condition of air in a space comprising:

a. means for conditioning primary air, b. terminal unit means in said space, c. means for transmitting the conditioned primary air from said conditioning means to the terminal unit, d. said terminal unit including, 1. a mixing duct having an inlet for air to be induced from said space and an outlet for conditioned supply air into said space, 2. a primary air plenum in communication with the conditioned air delivered to said terminal unit having nozzle means for introducing a constant relatively small proportion of the conditional primary air into the mixing duct to induce a flow of conditioned supply air from this mixing duct through said outlet into the space, 3. by-pass means in communication with the conditioned primary air delivered to the terminal unit and connected to the mixing duct for delivering a supply of damped conditioned primarY air into the mixing duct at a point spaced from and independent of the induction air delivered by the nozzle means, and 4. means responsive to changes in the thermal requirements of the space to be conditioned to regulate the conditioned primary air to be delivered by said by-pass means into the mixing duct relative the volume of air induced from the space through the inlet to the mixing duct whereby a constant volume of conditioned supply air including a ratio of by-pass conditioned air and induced space air is delivered by the terminal unit to obtain the necessary thermal capacity for meeting the cooling requirements of the space to be conditioned.

2. In the air condition system as claimed in claim 1 wherein the by-pass means is operatively connected to the primary plenum at one end and has an outlet communicating with the mixing duct at the said spaced point and the means responsive to the condition of the air in the space includes, a normally closed damper means disposed in the by-pass means, and an actuator for moving said damper means as a function of the variations in the thermal requirements of the space to be conditioned.

3. by-pass means in communication with the conditioned primary air delivered to the terminal unit and connected to the mixing duct for delivering a supply of damped conditioned primary air into the mixing duct at a point spaced from and independent of the induction air delivered by the nozzle means,

4. In an air conditioning system as claimed in claim 3 wherein said second damper means is positioned in the terminal unit to simultaneously and selectively vary the opening of the inlet for the mixing duct and the opening for the above-ceiling space in the terminal unit.

5. means responsive to the changes in the thermal requirements of the space to be conditioned to selectively and alternatively regulate the relative mixture of damped conditioned bypass air, the above-ceiling plenum air and air from said space entering the mixing duct whereby a constant volume of conditioned supply air is delivered from the mixing duct through said outlet into the space to meet the thermal requirements for selectively and alternatively cooling and heating said space as may be required.

6. An air conditioning system for controlling the condition of air in a space having a suspended ceiling defining an above-ceiling plenum space comprising:

a. means for conditioning primary air, b. terminal unit means in said space, c. means for transmitting the conditioned primary air from said conditioning means to the terminal unit, d. said terminal unit including,

7. In an air conditioning system as claimed in claim 6 further including:

a. means mounted adjacent the means forming the opening in the terminal unit for heating air passing therethrough, and b. means to control the operation of said heating means.

8. In a method of operating an air conditioning system for controlling the condition of air in a space the steps of:

conditioning primary air, transmitting the conditioned primary air to a terminal unit proximate the space to be conditioned, discharging a constant relatively small portion of said conditioned primary air in said terminal unit to induce the flow of air from said space into the terminal unit and the flow of conditioned supply air from the terminal unit into said space, damping the pressure and selectively by-passing varying volumes of conditioned primary air to a point in said terminal unit spaced from and independent of the induction air, controlling the relative volumetric proportions of by-passed damped conditioned primary air and the induced air from the space entering the unit to mix with said constant relatively small volume of induction air responsive to the thermal conditions in the space to be conditioned whereby when the temperature in said space rises above a predetermined cooling temperature level said control means will gradually increase the volumetric ratio of the damped conditioned air by-passed relative the air induced from the space and when it falls below this predetermined cooling level said control means will decrease the volumetric ratio of damped conditioned air by-passed relative the air induced from the space to continuously maintain delivery of a constant volume of conditioned supply air from the terminal unit for meeting the requirements for conditioning the air in said space.