ZONE TEMPERATURE CONTROL SYSTEM

• US 3,567,115 A
• Filed: 05/19/1969
• Issued: 03/02/1971
• Est. Priority Date: 05/19/1969
• Status: Expired due to Term

• Current Assignee: Lorne W. Nelson
• Original Assignee: Lorne W. Nelson
• Inventors: Nelson, Lorne W.
• Application Number:
  US04/825,899
• Time in Patent Office: 652 Days
• US Class Current: 236/1.00B
• CPC Class Codes: F24F 3/0522 in which warm or cold air from the central station is delivered via individual pipes to mixing chambers in the space to be treated, the cold air/warm air ratio being controlled by a thermostat in the space concerned, i.e. so-called Dual-duct System

Abstract

A zone temperature control system having a thermostat in each zone for controlling a supply of temperature changing medium to that zone. The thermostat having a first electrical output for modulatingly controlling the flow of medium to its zone and a second electrical output which can be selected when that zone has the greatest conditioning load to modulatingly control the temperature of the medium delivered to the plurality of zones from a central source.

Claims

1. A system for controlling a physical condition in a plurality of zones, comprising:

a first source of medium capable of effecting a change in the condition;

first circulating means for circulating the medium to the zones;

condition sensing means in each zone for sensing the condition in that zone and providing two outputs in accordance with the deviation between the sensed condition and a desired condition in that zone, said outputs depending on a first deviation range and a second deviation range;

flow control means for controlling the flow of medium to each zone in response to a first of said outputs of the sensing means in that zone whereby the flow of medium to each zone is controlled by said first output through said first range; and

first source control means for controlling the source to vary the condition changing capability of the medium in response to the second of said outputs whereby said condition changing capability of said first source is controlled by said second output through said second range.

2. The system of claim 1 wherein:

said condition sensing means is a zone thermostat having two switches each of which are cyclically closed by an amount proportional to the conditioning of load of said zone;

a first of said switches is connected to said flow control means whereby said first deviation increases the flow of medium to one of said zones to a predetermined amount; and

a second of said switches is connected to said first source control means whereby as said second deviation increases the temperature of the medium from said source is changed.

3. The system of claim 2 wherein:

said flow control means comprises damper means in a duct connecting said first source to said zone, said first switch controlling said damper from a closed to an open position through said first deviation range; and

said source control means comprising temperature control means for maintaining the temperature of the air delivered from a temperature conditioning source between a low value and a high value through said second deviation range whereby upon said damper in a duct of one zone reaches a predetermined position a further need for a change in condition of said one zone is brought about by the change in temperature of the air delivered.

4. The system of claim 2 wherein each of said zone thermostats comprises:

temperature responsive means responsive to each zone temperature;

heater means for artificially heating each of said temperature responsive means; and

means connecting each of said heater means to a source of power so that when said second switch of anY zone is closed said heater means of all temperature responsive means are energized to artificially heat said thermostat and to modify the control temperature of each temperature responsive means.

5. The system of claim 4 wherein:

third switch means connected to each damper means, said third switch means being closed where said damper means is in a predetermined position; and

circuit means including said third switch means of each zone for connecting said heater means to said source whereby said zone thermostats are not modified by said heater means unless a respective damper means is in a predetermined position.

6. In a multizone temperature control system for a temperature-conditioning system comprising:

a plurality of flow control means each adapted to control the supply of temperature conditioned medium from a temperature-conditioning apparatus to a respective zone;

a plurality of temperature responsive means each adapted to be responsive to the temperature in a zone, each of said temperature responsive means having an electrical output means, a first portion of said output means being actuated when the load of the zone is at first predetermined value and a second portion of said output means being actuated when the load of the zone is at a second predetermined value;

temperature control means adapted to control the temperature of medium delivered from the temperature-conditioning apparatus;

means connecting said first output means of each zone to control the operation of said flow control means of a respective zone; and

means connecting each said second output means of each zone to said temperature control means whereby upon any one of said first portion of said output means operating said flow control means of one of said zones to a predetermined open position, said second portion of said output means of said temperature responsive means of said one zone operates said temperature control means to change the temperature of the medium delivered from the temperature conditioning apparatus.

7. In the system of claim 6 wherein said temperature responsive means is adjusted whereby said first electrical output means is effective 100 percent of the time before said second electrical output means is effective.

8. In the system of claim 7 wherein said first output means is a first switch and said second output means is a second switch, and said temperature responsive means comprising a bimetal with the two switches mounted thereon, said first switch being closed 100 percent of the time before said second switch is closed to result in said flow control means of said zone to be completely energized before said temperature control means of the source is reset.

9. In the system of claim 1 wherein said first source control means controls the temperature of air for cooling said zones comprising:

first means to control the amount of outdoor air supplied to said first source;

second means for changing the temperature of the air of said first source; and

means including said first control means for controlling said first means and second means in sequence whereby outdoor air is first used for cooling.