# US 12,595,927 B2 · Method to control cleanroom conditions > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,595,927 B2 - Document ID: US12595927B2 - Status: Granted - Kind: B2 - Application number: 18/062,443 - Filed: 2022-12-06 - Published: 2023-04-13 - Granted: 2026-04-07 - Earliest claimed: 2018-12-19 - Assignees: Energy Efficiency Consultancy Group Limited - Applicants: Energy Efficiency Consultancy Group Limited - Inventors: Robert Wallace; Shuji Chen - Web page: https://patentgrep.com/patent/US12595927B2 ## CPC - F24F 3/163: Clean air work stations, i.e. selected areas within a space which filtered air is passed - F24F 11/54: using one central controller connected to several sub-controllers - F24F 11/46: Improving electric energy efficiency or saving - F24F 11/47: Responding to energy costs - 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 11/70: Control systems characterised by their outputs; Constructional details thereof - F24F 11/74: for controlling air flow rate or air velocity - F24F 2110/10: Temperature - F24F 2110/20: Humidity - F24F 2110/30: Velocity - F24F 2110/40: Pressure, e.g. wind pressure - F24F 2110/65: Concentration of specific substances or contaminants - F24F 2120/10: Occupancy - 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) ## Abstract The method to control cleanroom conditions, including zone particle concentration, occupancy status, and heating, ventilation, and air conditioning (HVAC) system conditions, includes detecting a zone particle concentration, an occupancy status, and HVAC system conditions. The cleanroom includes the HVAC system in communication with the zone of the cleanroom and with a computer processor as a control unit of the cleanroom. The zone particle concentration, the occupancy status, and the HVAC system conditions are communicated to the computer processor, and a desired zone particle concentration is determined based on a range of desired HVAC system conditions with model predictive control. A first control signal to the HVAC system based on the occupancy status, the zone particle concentration, and the desired zone particle concentration is determined. The first control signal is communicated to the HVAC system, and the HVAC system activates according to the first control signal. ## Claims ### Claim 1 A method to control cleanroom conditions, the method comprising the steps of: detecting a first zone particle concentration in a zone of a cleanroom with a particle sensor within said zone of said cleanroom; detecting a first occupancy status in said zone of said cleanroom with an occupancy sensor within said zone of said cleanroom; detecting heating, ventilation, and air conditioning (HVAC) system conditions in said zone of said cleanroom with a plurality of HVAC sensors, wherein said cleanroom is comprised of an HVAC system in communication with said zone of said cleanroom and with a computer processor, and wherein said particle sensor, said occupancy sensor and said plurality of HVAC sensors are in communication with said computer processor; communicating said first zone particle concentration, said first occupancy status, and the HVAC system conditions to said computer processor; determining a first desired zone particle concentration in said zone based on a range of desired HVAC system conditions according to said first occupancy status with said computer processor; determining a first control signal to the HVAC system based on said first occupancy status, said first zone particle concentration, and said first desired zone particle concentration; communicating said first control signal to the HVAC system; activating the HVAC system according to said first control signal; detecting a second zone particle concentration in said zone of said cleanroom with said particle sensor within said zone of said cleanroom, after the step of activating the HVAC system according to said first control signal; detecting a second occupancy status in said zone of said cleanroom with said occupancy sensor within said zone of said cleanroom; detecting second HVAC system conditions in said zone of said cleanroom with said plurality of HVAC sensors; communicating said second zone particle concentration, said second occupancy status, and the second HVAC system conditions to said computer processor: determining a second control signal to the HVAC system based on said first occupancy status, said second occupancy status, said first zone particle concentration, said second zone particle concentration, said first control signal, and said first desired zone particle concentration when said first occupancy status and said second occupancy status are identical; communicating said second control signal to the HVAC system; and activating the HVAC system according to said second control signal. ### Claim 2 (depends on 1) The method to control cleanroom conditions, according to claim 1, further comprising the steps of: detecting a third zone particle concentration in said zone of said cleanroom with said particle sensor within said zone of said cleanroom, after the step of activating the HVAC system according to said second control signal; detecting a third occupancy status in said zone of said cleanroom with said occupancy sensor within said zone of said cleanroom; detecting third HVAC system conditions in said zone of said cleanroom with said plurality of HVAC sensors; communicating said third zone particle concentration, said third occupancy status, and the third HVAC system conditions to said computer processor; determining a third control signal to the HVAC system based on said first occupancy status, said second occupancy status, said third occupancy status, said first zone particle concentration, said second zone particle concentration, said third zone particle concentration, said first control signal, said second control signal, and said first desired zone particle concentration when said first occupancy status, said second occupancy status, and said third occupancy status are identical; communicating said third control signal to the HVAC system; and activating the HVAC system according to said third control signal. ### Claim 3 (depends on 1) The method to control cleanroom conditions, according to claim 1, further comprising the steps of: detecting a third zone particle concentration in said zone of said cleanroom with said particle sensor within said zone of said cleanroom, after the step of activating the HVAC system according to said second control signal; detecting a third occupancy status in said zone of said cleanroom with said occupancy sensor within said zone of said cleanroom; detecting third HVAC system conditions in said zone of said cleanroom with said plurality of HVAC sensors; communicating said third zone particle concentration, said third occupancy status, and the third HVAC system conditions to said computer processor; determining a second desired zone particle concentration in said zone based on said range of desired HVAC system conditions according to said third occupancy status with said computer processor when said first occupancy status and said second occupancy status is different from said third occupancy status; determining a second control signal to the HVAC system based on said third occupancy status, said first zone particle concentration, said second zone particle concentration, said third zone particle concentration, said first desired zone particle concentration, said first control signal, said second control signal, and said second desired zone particle concentration; communicating said third control signal to the HVAC system; and activating the HVAC system according to said third control signal. ### Claim 4 (depends on 1) The method to control cleanroom conditions, according to claim 1, wherein the HVAC system conditions are air flow rate, air pressure, temperature, and humidity. ### Claim 5 (depends on 1) The method to control cleanroom conditions, according to claim 1, wherein the HVAC system is comprised of an air duct, an air handling unit, and an air volume device. ### Claim 6 (depends on 5) The method to control cleanroom conditions, according to claim 5, wherein said air volume device is comprised of a constant air volume device, a variable air volume device or both, and wherein said first control signal corresponds to at least of a group consisting of: said air handling unit, said constant air volume device, and said variable air volume device. ### Claim 7 (depends on 6) The method to control cleanroom conditions, according to claim 6, wherein said first control signal corresponds to drivers for said air handling unit, said constant air volume device, and said variable air volume device. ### Claim 8 (depends on 5) The method to control cleanroom conditions, according to claim 5, wherein said air handling unit is comprised of a pre-filter, a secondary filter, a main air blower, a temperature device and a high-efficiency particulate air (HEPA) filter element. ### Claim 9 (depends on 8) The method to control cleanroom conditions, according to claim 8, wherein a temperature device is comprised of a heating element, a cooling element or both. ### Claim 10 (depends on 5) The method to control cleanroom conditions, according to claim 5, wherein a building management system is comprised of at least one of said air duct, said air handling unit, and said air volume device. ### Claim 11 (depends on 1) The method to control cleanroom conditions, according to claim 1, wherein an HVAC sensor of said plurality of HVAC sensors is selected from a group consisting of: an air flow rate sensor, an air pressure sensor, a temperature sensor, and a humidity sensor. ### Claim 12 (depends on 1) The method to control cleanroom conditions, according to claim 1, wherein the step of determining said first desired zone particle concentration is further based on a predictive model for the HVAC system conditions. ### Claim 13 (depends on 1) The method to control cleanroom conditions, according to claim 1, wherein the step of determining said first desired zone particle concentration is further based on energy savings of the HVAC system. ### Claim 14 (depends on 1) The method to control cleanroom conditions, according to claim 1, wherein the step of determining said first desired zone particle concentration is further based on cost efficiency of the HVAC system. ### Claim 15 A method to control cleanroom conditions, the method comprising the steps of: detecting a first zone particle concentration in a zone of a cleanroom with a particle sensor within said zone of said cleanroom; detecting a first occupancy status in said zone of said cleanroom with an occupancy sensor within said zone of said cleanroom; detecting heating, ventilation, and air conditioning (HVAC) system conditions in said zone of said cleanroom with a plurality of HVAC sensors, wherein said cleanroom is comprised of an HVAC system in communication with said zone of said cleanroom and with a computer processor, and wherein said particle sensor, said occupancy sensor and said plurality of HVAC sensors are in communication with said computer processor; communicating said first zone particle concentration, said first occupancy status, and the HVAC system conditions to said computer processor; determining a first desired zone particle concentration in said zone based on a range of desired HVAC system conditions according to said first occupancy status with said computer processor; determining a first control signal to the HVAC system based on said first occupancy status, said first zone particle concentration, and said first desired zone particle concentration; communicating said first control signal to the HVAC system; activating the HVAC system according to said first control signal; detecting a second zone particle concentration in said zone of said cleanroom with said particle sensor within said zone of said cleanroom, after the step of activating the HVAC system according to said first control signal; detecting a second occupancy status in said zone of said cleanroom with said occupancy sensor within said zone of said cleanroom; detecting second HVAC system conditions in said zone of said cleanroom with said plurality of HVAC sensors; communicating said second zone particle concentration, said second occupancy status, and the second HVAC system conditions to said computer processor; determining a second desired zone particle concentration in said zone based on said range of desired HVAC system conditions according to said second occupancy status with said computer processor when said first occupancy status is different from said second occupancy status; determining a second control signal to the HVAC system based on said second occupancy status, said first zone particle concentration, said second zone particle concentration, said first desired zone particle concentration, said first control signal, and said second desired zone particle concentration; communicating said second control signal to the HVAC system; and activating the HVAC system according to said second control signal. ### Claim 16 (depends on 15) The method to control cleanroom conditions, according to claim 15, wherein the HVAC system conditions are air flow rate, air pressure, temperature, and humidity. ### Claim 17 (depends on 15) The method to control cleanroom conditions, according to claim 15, wherein the HVAC system is comprised of an air duct, an air handling unit, and an air volume device. ### Claim 18 (depends on 15) The method to control cleanroom conditions, according to claim 15, wherein an HVAC sensor of said plurality of HVAC sensors is selected from a group consisting of: an air flow rate sensor, an air pressure sensor, a temperature sensor, and a humidity sensor. ### Claim 19 (depends on 15) The method to control cleanroom conditions, according to claim 15, wherein the step of determining said first desired zone particle concentration is further based on a predictive model for the HVAC system conditions. ### Claim 20 (depends on 15) The method to control cleanroom conditions, according to claim 15, wherein the step of determining said first desired zone particle concentration is further based on energy savings of the HVAC system.