# US 10,480,807 B2 · HVAC systems and methods with refrigerant leak detection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,480,807 B2 - Document ID: US10480807B2 - Status: Granted - Kind: B2 - Application number: 15/851,731 - Filed: 2017-12-21 - Published: 2018-05-03 - Granted: 2019-11-19 - Earliest claimed: 2014-06-13 - Assignees: Lennox Industries Inc. - Applicants: Lennox Industries Inc. - Inventors: Rakesh Goel; Mark Olsen; Hermon Alan Boyd - Web page: https://patentgrep.com/patent/US10480807B2 ## CPC - F24F 11/36: to leakage of heat-exchange fluid - F24F 11/30: for purposes related to the operation of the system, e.g. for safety or monitoring - F24F 11/33: to fire, excessive heat or smoke - F24F 11/38: Failure diagnosis - F24F 11/52: Indication arrangements, e.g. displays - F24F 11/62: characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values - F24F 11/63: Electronic processing - F24F 11/77: by controlling the speed of ventilators - F24F 11/83: by controlling the supply of heat-exchange fluids to heat-exchangers - G01M 3/04: by detecting the presence of fluid at the leakage point - F24F 11/86: by controlling compressors within refrigeration or heat pump circuits - F24F 2110/00: Control inputs relating to air properties - F25B 1/00: Compression machines, plants or systems with non-reversible cycle (F25B3/00, F25B5/00, F25B6/00, F25B7/00, F25B9/00 take precedence) - F25B 2400/12: Inflammable refrigerants - Y02B 30/70: Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating - F24F: AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B15/00; vertical ducts for carrying away waste gases from buildings E04F17/02; tops for chimneys or ventilating shafts, terminals for flues F23L17/02) - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract Systems and methods are disclosed that involve detecting a flammable refrigerant associated with a heating, ventilating, and air conditioning (HVAC) system. In one instance a damper covers an access port allowing a single sensor to monitor at least two separate spaces. In another instance, a multi-probe sensor allows a single sensor to monitor at least two separate spaces. ## Claims ### Claim 1 An HVAC system for providing conditioned air to a first closed space, wherein at least a portion of the system is disposed within a second closed space, the system comprising: an HVAC unit comprising: a return air duct, a blower fluidly coupled to the return air duct for pulling air through the return air duct, a conditioning compartment comprising a plurality of walls, wherein the conditioning compartment is fluidly coupled to the blower for receiving air therefrom to be treated, a cooling unit fluidly coupled to the conditioning compartment for selectively cooling air therein, wherein the cooling unit comprises a flammable refrigerant, and a delivery duct fluidly coupled to the conditioning compartment for discharging treated air from the conditioning compartment into the first closed space; a flammable-component detector comprising at least one sensor, wherein the flammable-component detector is operable to produce a detection signal indicative of the level of a flammable component detected by the flammable-component detector; a first probe fluidly coupled to the flammable-component detector and to the conditioning compartment; a second probe fluidly coupled to the flammable-component detector and to the second closed space; a selector, wherein each of the first probe and the second probe is selectively fluidly coupled, one at a time, by the selector to the flammable-component detector; and a processing unit comprising at least one processor and at least one memory, the processing unit communicatively coupled to the flammable-component detector for receiving a detection signal therefrom, and wherein the at least one processor and at least one memory is operable to perform the following steps: monitor the detection signal, and send an alert when the detection signal is indicative of the concentration of a flammable component being at least equal to an alert threshold. ### Claim 2 (depends on 1) The system of claim 1, wherein the selector is a plurality of control valves. ### Claim 3 (depends on 1) The system of claim 1, wherein the selector is a plurality of sample blowers, wherein a first sample blower of the plurality of sample blowers is associated with the first probe and a second sample blower of the plurality of sample blowers is associated with the second probe. ### Claim 4 (depends on 1) The system of claim 1, wherein the system comprises only two probes, the first probe and the second probe, and wherein each of the two probes is selectively fluidly coupled one at a time to the flammable-component detector, and wherein the alert threshold is one-half of the base threshold for the flammable-component detector having only a single probe. ### Claim 5 (depends on 1) The system of claim 1, further comprising a third probe fluidly coupled to the flammable-component detector and to a third closed space, wherein the system comprises only three probes, which includes the first probe, second probe, and the third probe, and wherein each of the three probes is selectively fluidly coupled one at time to the flammable-component detector, and wherein the alert threshold is one-third of the base threshold for the flammable-component detector having only a single probe. ### Claim 6 (depends on 1) The system of claim 1, wherein the HVAC unit further comprises a heating device fluidly coupled to the conditioning compartment for selectively heating air therein.