Integrating room space pressure measurements with hvac controls

Abstract

A substantially tubeless and wireless system accurately measures differential air pressures at several different indoor points relative to outside air. In some embodiments, individual units (e.g., receivers and/or zone transmitters) apply an algorithm to derive the air pressure in the space in which the unit is installed. If the derived pressure is at or near the outside pressure, the unit starts a counter to measure the length of time the equalized pressure condition exists. If the condition persists longer than the time it takes to egress or ingress through a door or to open and close a window, a flag signal is sent to the unit. The unit then takes action to halt cooling or heating in the space. In some embodiments, the unit may be a thermostat, or HVAC controlling device or cloud acting as a HVAC controller. Notification to the end user of the action taken may be provided on the thermostat panel or through a mobile application or other available source.

What is claimed is: 
     
         1 . A system, comprising:
 a plurality of transmitters that respectively comprise:
 one or more processors; 
 an absolute pressure sensor; and 
 memory storing computer-readable instructions that, if executed by the one or more processors, cause the one or more processors to perform operations comprising:
 receiving an outside absolute air pressure; 
 determining a local absolute air pressure; 
 deriving an air pressure differential between the outside absolute air pressure and the local absolute air pressure; 
 transmitting the derived differential pressure to a receiver; and 
 
   the receiver that comprises:
 one or more processors; 
 an absolute pressure sensor; and 
 memory storing computer-readable instructions that, if executed by the one or more processors, cause the one or more processors to perform operations comprising:
 receiving the derived differential pressures from the transmitters; 
 comparing the differential pressures to a predetermined threshold; 
 determining whether any of the differential pressures is less than the predetermined threshold; 
 for each differential pressure that is less than the predetermined threshold:
 determining the time that the differential pressure exists; 
 comparing the time to a wait threshold; and 
 for any differential pressure that exists for longer than the time threshold, turn off a mode for the space in which the transmitter that supplied the differential pressure is located.