# US 2025/0155902 A1 · Gas sensing leak mitigation unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0155902 A1 - Document ID: US20250155902A1 - Status: Published application - Kind: A1 - Application number: 18/505,565 - Filed: 2023-11-09 - Published: 2025-05-15 - Earliest claimed: 2023-11-09 - Applicants: Danfoss A/S - Inventors: Mark Eric Miller; Wayne Edgar Alphonso - Web page: https://patentgrep.com/patent/US20250155902A1 ## CPC - F25B 49/005: {of safety devices (F25B49/02 and F25B49/04 take precedence)} - G05D 7/0676: {by action on flow sources (G05D7/0688, G05D7/0694 take precedence)} - F24D 19/1084: {for air heating systems} - F25B 2500/221: Preventing leaks from developing - F25B 2500/222: Detecting refrigerant leaks - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - F24D: DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR (using steam or condensate extracted or exhausted from steam engine plants for heating purposes F01K17/02) ## Abstract A gas sensing leak mitigation unit for a gas system includes a gas sensing element, at least one onboard relay, and at least one microcontroller. The at least one microcontroller is configured to receive a signal from the gas sensing element and to determine if the signal from the gas sensing element is above a first predetermined threshold level. The at least one microcontroller is further configured to control the energizing and de-energizing of the onboard relays. A first onboard relay may be configured, when energized, to transmit power to a compressor of the gas system and, when de-energized, to break power to the compressor. A second onboard relay may be configured, when de-energized, to transmit power to a fan control. The gas sensing element, the at least one onboard relay and the at least one microcontroller may all be arranged within a common housing. ## Claims ### Claim 1 A gas sensing leak mitigation unit for a gas system, the gas sensing leak mitigation unit comprising: a gas sensing element; one or more microcontrollers configured to receive a signal from the gas sensing element and to determine if the signal from the gas sensing element is above a first predetermined threshold level; a first relay configured, when energized, to transmit power to a compressor and, when de-energized, to break power to the compressor; the one or more microcontrollers configured to control the energizing and de-energizing of the first relay; and wherein the gas sensing element, the one or more microcontrollers, and the first relay are all arranged within a common housing. ### Claim 2 (depends on 1) The gas sensing leak mitigation unit according to claim 1: wherein the one or more microcontrollers are configured to transmit an alarm condition signal to a system controller, the system controller being configured to control the gas system, when the one or more microcontrollers determine that the signal from the gas sensing element is above a first predetermined threshold level. ### Claim 3 (depends on 1) The gas sensing leak mitigation unit according to claim 1: wherein the one or more microcontrollers are configured to energize the first relay to thereby transmit electrical power to the compressor during a normal operating condition of the system; and wherein the one or more microcontrollers are configured to de-energize the first relay to thereby break the transmission of electrical power to the compressor when the one or more microcontrollers determine that the signal from the gas sensing element is above the first predetermined threshold level. ### Claim 4 (depends on 1) The gas sensing leak mitigation unit according to claim 1, further comprising: a second relay configured, when de-energized, to transmit power to a fan controller; wherein the one or more microcontrollers are configured to control the energizing and de-energizing of the second relay; and wherein the one or more microcontrollers are configured to de-energize the second relay when the signal from the gas sensing element is above the first predetermined threshold level. ### Claim 5 (depends on 1) The gas sensing leak mitigation unit according to claim 1: wherein the one or more microcontrollers are configured to receive a signal from the gas sensing element and to determine if the signal from the gas sensing element is below a second predetermined threshold level, which second predetermined threshold level is less than or equal to the first predetermined threshold level; and wherein the one or more microcontrollers are configured to start a predetermined time delay countdown when the one or more microcontrollers determine that the signal from the gas sensing element is below the second predetermined threshold level. ### Claim 6 (depends on 5) The gas sensing leak mitigation unit according to claim 5: wherein the one or more microcontrollers are configured to keep the first relay de-energized during the predetermined time delay countdown; and wherein the one or more microcontrollers are configured to energize the first relay when the predetermined time delay has elapsed. ### Claim 7 (depends on 4) The gas sensing leak mitigation unit according to claim 4: wherein the one or more microcontrollers are configured to receive a signal from the gas sensing element and to determine if the signal from the gas sensing element is below a second predetermined threshold level, which second predetermined threshold level is less than or equal to the first predetermined threshold level; and wherein the one or more microcontrollers are configured to start a predetermined time delay countdown when the one or more microcontrollers determine that the signal from the gas sensing element is below the second predetermined threshold level. ### Claim 8 (depends on 7) The gas sensing leak mitigation unit according to claim 7: wherein the one or more microcontrollers are configured to keep both the first relay and the second relay de-energized during the predetermined time delay countdown; and wherein the one or more microcontrollers are configured to energize both the first relay and the second relay when the predetermined time delay has elapsed. ### Claim 9 A gas sensing leak mitigation unit for a gas system, the gas sensing leak mitigation unit comprising: a gas sensing element; a first relay configured, when energized, to transmit power to a compressor and, when de-energized, to break power to the compressor; a second relay configured, when de-energized, to transmit power to a fan control; at least one microcontroller configured to receive a signal from the gas sensing element and to determine if the signal from the gas sensing element is above a first predetermined threshold level; wherein the at least one microcontroller is further configured to control the energizing and de-energizing of the first and second relays; wherein the gas sensing element, the at least one microcontroller, and the first and second relays are all arranged within a common housing. ### Claim 10 (depends on 9) The gas sensing leak mitigation unit according to claim 9: wherein the at least one microcontroller is configured to transmit an alarm condition signal to a system controller, the system controller being configured to control the gas system, when the at least one microcontroller determines that the signal from the gas sensing element is above a first predetermined threshold level. ### Claim 11 (depends on 9) The gas sensing leak mitigation unit according to claim 9: wherein the at least one microcontroller is configured to energize the first relay to thereby transmit electrical power to the compressor during a normal operating condition of the system; and wherein the at least one microcontroller is further configured to de-energize the first relay to thereby break the transmission of electrical power to the compressor when the at least one microcontroller determines that the signal from the gas sensing element is above the first predetermined threshold level. ### Claim 12 (depends on 9) The gas sensing leak mitigation unit according to claim 9: wherein the at least one microcontroller is configured to de-energize the second relay when the signal from the gas sensing element is above the first predetermined threshold level. ### Claim 13 (depends on 9) The gas sensing leak mitigation unit according to claim 9: wherein the at least one microcontroller is configured to receive a signal from the gas sensing element and to determine if the signal from the gas sensing element is below a second predetermined threshold level, which second predetermined threshold level is less than or equal to the first predetermined threshold level; and wherein the at least one microcontroller is configured to start a predetermined time delay countdown when the at least one microcontroller determines that the signal from the gas sensing element is below the second predetermined threshold level. ### Claim 14 (depends on 13) The gas sensing leak mitigation unit according to claim 13: wherein the at least one microcontroller is configured to keep both the first and second relays de-energized during the predetermined time delay countdown; and wherein the at least one microcontroller is configured to energize both the first and second relays when the predetermined time delay has elapsed. ### Claim 15 (depends on 1) A heat pump having the gas sensing leak mitigation unit according to claim 1. ### Claim 16 (depends on 9) A heat pump having the gas sensing leak mitigation unit according to claim 9. ### Claim 17 (depends on 1) A gas furnace having the gas sensing leak mitigation unit according to claim 1. ### Claim 18 (depends on 9) A gas furnace having the gas sensing leak mitigation unit according to claim 9.