Air conditioning/heating airflow control method and system

• US 10,359,202 B1
• Filed: 10/30/2018
• Issued: 07/23/2019
• Est. Priority Date: 10/30/2018
• Status: Active Grant

• Current Assignee: Donald B. Prather
• Original Assignee: Donald B. Prather
• Inventors: Prather, Donald B.
• Primary Examiner(s): Everett, Christopher E.
• Application Number:
  US16/174,650
• Time in Patent Office: 266 Days
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/72 for controlling the supply of treated air, e.g. its pressure
• CPC Class Codes: F24F 11/76 by means responsive to temperature, e.g. bimetal springs
• CPC Class Codes: F24F 13/06 Outlets for directing or distributing air into rooms or spaces, e.g. ceiling air diffuser
• CPC Class Codes: F24F 3/00 Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems room units F24F1/00
• 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: F24F 5/001 Compression cycle type
• CPC Class Codes: G05B 19/042 using digital processors G05B19/05 takes precedence
• CPC Class Codes: G05B 2219/2614 HVAC, heating, ventillation, climate control

Abstract

Individual zone temperature control sensors in a multiple zone system are monitored by a controller, and when one zone calls, the calling zone is allocated all of the airflow from the HVAC system except for a predetermined minimum that is allocated to the other zones. If all zones have equal priority, then the airflow continues to be supplied to the first calling zone until a temperature condition is satisfied, at which time the full airflow is allocated to a second calling zone and only the predetermined minimum is supplied to the first and all other calling zones. When two or more zones having different priorities, or set point deviations, are calling at the same time, the zone with the highest priority or whose temperature is furthest from a set point will become the single zone that is open and receives all of the air except for the predetermined minimum. Air continues to be supplied to that zone until it has achieved a desired temperature, until a higher priority zone calls, or until another zone is furthest from the set point. In order to provide maximum airflow to single zones according to the method of the invention, duct and outlet sizes must be larger than is necessary for conventional systems in which more than the minimum airflow is simultaneously allocated to multiple zones. Instead of utilizing conventional duct size calculations that assume simultaneous allocation of airflow to multiple zones, the design sizes the ducts in each zone to carry 100% of the system'"'"'s airflow less the predetermined minimum.

Claims

1. A method of controlling airflow in a multiple zone heating/air conditioning system, comprising the steps of:

monitoring individual zone temperature control sensors by a controller, and when a sensor in a first calling zone sends a signal indicating that a temperature in the first calling zone is above or below a set point by a predetermined amount, operating a heating or cooling unit to heat or cool air and supplying the heated or cooled air to diffusers in the first calling zone via ducts, wherein the first calling zone is allocated all of the airflow output by the heating or cooling unit except for a predetermined minimum airflow output that is allocated to all other zones; and

maintaining allocation of all of the airflow output to the first calling zone except for the predetermined minimum airflow output and preventing more than the predetermined minimum airflow output from being allocated to all other calling zones until the temperature in the first calling zone reaches a desired temperature,

wherein the step of terminating the allocation of all of the airflow output except for the predetermined minimum airflow output to the first calling zone and instead supplying all of the airflow output except for the predetermined minimum airflow output to a second calling zone is accomplished by permitting diffusers in the first calling zone to remain open until diffusers in the second calling zone are fully open, and only then closing the dampers in the first calling zone to avoid over pressurization of the ducts.

2. A method of controlling airflow in a multiple zone heating/air conditioning system as claimed in claim 1, further comprising the step of terminating the full allocation of all of the airflow output except for the predetermined minimum airflow output to the first calling zone and instead supplying all of the airflow output except for the predetermined minimum airflow output to a second calling zone when the second calling zone has a priority that is higher than a priority of the first calling zone.

3. A method of controlling airflow in a multiple zone heating/air conditioning system as claimed in claim 1, further comprising the step of terminating the full allocation of all of the airflow output except for the predetermined minimum airflow output to the first calling zone and instead supplying all of the airflow output except for the predetermined minimum airflow output to a second calling zone when a temperature in the second calling zone deviates by a greater amount from a set point in the second calling zone than the temperature in the first calling zone deviates from the set point in the first calling zone.

4. A method of controlling airflow in a multiple zone heating/air conditioning system as claimed in 1, further comprising a step of delaying restart of the condenser after the temperature of the first calling zone has reached a predetermined temperature and no other zone has called.

5. A multiple zone heating and air conditioning system, comprising a plurality of ducts, diffusers and temperature control sensors with user-established set points in each zone, the diffusers being opened and closed by a central controller, wherein the central controller is programmed to execute instructions for controlling opening and closing of the ducts according to the following sequence of steps:

monitoring the zone temperature control sensors, and

when a sensor in a first calling zone sends a signal indicating that a temperature in the first calling zone is above or below a set point by a predetermined amount, operating a heating or cooling unit to heat or cool air and supplying the heated or cooled air to diffusers in the first calling zone via ducts,

wherein the first calling zone is allocated all of the airflow output by the heating or cooling unit except for the minimum airflow that is distributed to the other zones,

wherein the controller is further programmed to execute instructions for terminating the allocation of all of the airflow output except for the predetermined minimum airflow output to the first calling zone and instead supplying all of the airflow output except for the predetermined minimum airflow output to a second calling zone by permitting diffusers in the first calling zone to remain open until diffusers in the second calling zone are fully open, and only then closing the dampers in the first calling zone to avoid over pressurization of the ducts, and

wherein the ducts and diffusers in respective zones are arranged to accommodate an enlarged air flow calculated based on the formula;

Zone CFM=Total CFM−

Minimum CFM 

 

(1)

where “

Zone CFM”

is an airflow allocated by a central controller to the zone, “

Total CFM”

is a total output of a central heating and/or air conditioning unit, and “

Minimum CFM”

is a minimum airflow distributed to other zones to ensure minimum adequate ventilation.

6. A multiple zone heating and air conditioning system as claimed in claim 5, wherein the minimum airflow is approximately 10% of “

Total CFM”

.

7. A multiple zone heating and air conditioning system as claimed in claim 5, wherein the controller is further programmed to execute instructions for terminating the allocation of all of the airflow output except for the minimum airflow to the first calling zone and supplying all of the airflow output except for the minimum airflow to a second calling zone when the second calling zone has a priority that is higher than a priority of the first calling zone.

8. A multiple zone heating and air conditioning system as claimed in claim 5, wherein the controller is further programmed to execute instructions for terminating the allocation of all of the airflow output except for the predetermined minimum airflow output to the first calling zone and instead supplying all of the airflow output except for the predetermined minimum airflow output to a second calling zone when a temperature in the second calling zone deviates by a greater amount from a set point in the second calling zone than the temperature in the first calling zone deviates from the set point in the first calling zone.

9. A multiple zone heating and air conditioning system as claimed in claim 5, wherein the controller is further programmed to execute instructions for delaying restart of the condenser after the temperature of the first calling zone has reached a predetermined temperature and no other zone has called.