Air conditioner

• US 5,076,346 A
• Filed: 07/23/1990
• Issued: 12/31/1991
• Est. Priority Date: 06/17/1987
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Otsuka, Nobuo
• Primary Examiner(s): FORD, JOHN K
• Application Number:
  US07/556,382
• Time in Patent Office: 526 Days
• Field of Search: 165/22, 165/16, 236/49.3, 236/1 B, 236/1 C
• US Class Current: 165/217
• CPC Class Codes: F24F 11/89 Arrangement or mounting of control or safety devices
• CPC Class Codes: F24F 3/044 Systems in which all treatment is given in the central station, i.e. all-air systems
• CPC Class Codes: G05D 23/1934 each space being provided with one sensor acting on one or more control means

Abstract

A duct type of air conditioner wherein temperature in a plurality rooms are controlled independently, and which after having controlled opening and closing of dampers for the rooms, is capable of controlling air volume, controlling the opening and closing of each damper depending on the temperature in the room with the corresponding damper, or determining atuomatically whether to select heating and cooling, depending on each room temperature and an external air, thereby realizing an optimum and effective operation control. When the total opening degree of the dampers becomes less than a predetermined amount the opening degree of the damper feeding air to the room with the greatest heat load is revised to be open.

Claims

1. A system for cooling and heating, comprising:

a heat source device having means for producing heated and cooled air,

an air blower for feeding heated air and cooled air,

a duct with branch ducts for directing the heated air and cooled air,

dampers arranged in the branch ducts,

room thermostats arranged in rooms,

heat load measuring means for detecting signals from the room thermostats, measuring the heat load of each room and arranging said heat loads in order of magnitude,

damper opening determining means for carrying out a room temperature control based on the results of the measurement by the heat load measuring means,

damper opening revision means for revising an opening degree of the damper for the room with the greatest heat load to be open when a value of the total opening degrees of the dampers given by the room temperature control of the damper opening determining means is not higher than a predetermined value, and

damper control means for controlling the opening and closing of the damper of each room based on the output of the damper opening revision means.

2. A system according to claim 1, wherein the heat load measuring means is constructed so that signals indicative of the room temperature T(I) and the set room temperature R(I) from each room thermostat (I) are detected, the heat load of each room is the difference D(I) between the set temperature T(I) and the set room temperature R(I).

3. A system according to claim 2, wherein the damper opening determining means is constructed such that the opening and closing of the damper of each room is decided. so that the temperature in each room comes into the range of R(I)+A and R(I)-B.

4. A system according to claim 1, wherein the damper opening revising means is constructed so that the minimum value of the total opening degrees of dampers depends on the number of the dampers and when the value of the total opening degrees determined by the damper opening determining means becomes lower than said minimum value of the total opening degrees, the damper for the room having the greatest heat load is revised to be open with additional rooms being revised to be opened until said minimum value of the total opening degrees is reached.

5. A system according to claim 4, wherein the damper opening revising means is constructed so that when the value of the total opening degrees of the dampers is 100%, and 200% is said minimum value of the total opening degrees, the damper for the room with the greatest heat load and the damper for the room with the second greatest head load are revised to be open.

6. A system according to claim 4, wherein the damper opening revising means is constructed so that when the value of the total opening degrees of the dampers is zero % (all the dampers are closed, and 100% is said minimum value of the total opening degrees, and when the temperature in the room with the greatest heat load is lower R(I)+A (at the time of the heating) or higher than R(I)-B (at the time of cooling), where R(I) is the set room temperature for each room thermostat and A and B are fixed values the damper for said room with the greatest heat load is revised to be open.

7. A system according to claim 4, wherein the damper opening revising means is constructed so that when the value of the total opening degrees of the dampers is zero %, and 200% is said minimum value of the total opening degrees and when the temperature in the rooms with the greatest heat load is lower than R(I)+A (at the time of heating) or higher than R(I)-B (at the time of cooling), where R(I) is the set room temperature for each room thermostat and A and B are fixed values the damper for said rooms with the greatest heat load and the second greatest heat load are revised to be open.

8. A system according to claim 7, wherein the damper opening revising means is constructed so that when the value of the total opening degrees of the dampers is 100% or zero %, and 200% is said minimum value of the total opening degrees, the greatest heat load D(I) is compared to the second greatest heat load D(I), where D(I) is the difference between the set temperature and the room temperature for each room thermostat to determine whether the dampers of these rooms are revised to be open or all the dampers are revised to be closed.