Table 2.
Sensors employed by novel air conditioning system and achieved smart control.
| Year | Air Conditioning Case | Equipped Sensors | Achieved Smart Control | ||
|---|---|---|---|---|---|
| Thermo-Fluidic | Occupancy Detection | Others | |||
| 1982–1983 | EMS for Heating/ventilating/air conditioning equipment: Case study of USA [55,56] | Thermocouples + Multiplexor + Minicomputer system | X | X | Using a computer for supervisory control allows the equipment to be operated in a more efficient manner through temperature sensor feedback controls |
| 1985 | Energy management for air conditioning system in Kuwait [57] | RTDs with accuracy to 0.1 °C temperature sensing | X | Water flow rate sensor | Energy management and economic analysis based on occupancy periods and the present values of life-cycle costs |
| 1986 | Computerized energy management system installed in the small to large industries and campus type facilities [28] | RTDs + Micro- and minicomputers with 4–10 floating per unit | PIR sensor + hardware digital equipment | X | Hardware digital equipment with occupancy detection function for start/stop of equipment and stand-alone demand controller |
| 1986 | Thermostat management for reducing household energy [58] | Thermostat based on thermistor | Home ownership investigation | X | Self-reported winter and summer thermostat settings and control strategies according to sensor data and occupancy status |
| 1992 | Users’ decisions about when and how to operate room air conditioners [59] | Thermostat based on thermistor + Wind velocity indicator | X | X | By user education, resident can operate air conditioner by non-thermostatic mode. |
| 1993 | Energy management for multi-zone air conditioning systems in Canada [60] | Thermistors with accuracy to 0.5 °C temperature sensing | X | Disturbance input | Multi-zone control based temperature sensor and disturbance signal |
| 1994 | A two zone variable air volume system [61] | Supply, return, entering and leaving air condition sensors include air density, velocity, temperature and humidity | Input data related to occupied period | X | A reduced model for variable air volume system to account mass, momentum and energy balance for saving energy |
| 1994 | Comfort control for short term occupancy at hotel [62] | Thermostat based on thermistor | PIR sensor integrated in a prototype ‘comfortstat’ | X | Interactive set-point adjustment with immediate response to thermal requests |
| 1996 | Optimization of thermal processes in a variable air volume system [63] | Thermistors with accuracy to 0.5 °C temperature sensing + Humidity sensor | Thermal load prediction | X | Optimized thermal processes to achieve thermal comfort by both zone temperature and humidity ratio |
| 1999 | On-line control strategies for air conditioning system [64] | RTDs with accuracy to 0.1 °C temperature sensing + Air flow rate sensor + Pressure sensor | Investigating number of occupants | CO2 sensor | Optimizing pressure set-point of variable air volume system to achieve thermal comfort and improve air quality |
| 2001 | Air conditioning control to ensure comfort [65] | RTDs with accuracy to 0.01 °C temperature sensing | CO2 detection for improved start-stop time control | Integrated IAQ sensor | Air bypass, CO2 control, setback and improved start-stop time |
| 2005 | Personalized ventilation for air conditioning in a hot and humid climate [66] | Thermistors with accuracy to 0.5 °C temperature sensing + Air flow rate sensor with resolution to 0.01 L/s | Investigating number of occupants and detailed data includes sex, age, height and weight | X | Personalized ventilation to improve the immediate breathing zones of occupants in the built environment |
| 2006 | Optimal set point strategy to achieve energy efficient operation of air conditioning system [67] | Thermistors with accuracy to 0.5 °C temperature sensing | Occupied time adaptive controller based year-month-day function | X | Occupied time adaptive control and energy efficiency through optimal set point |
| 2008 | Energy saving and improved comfort by increased air movement [68] | RTDs with accuracy to 0.1 °C temperature sensing + wind velocity sensor with resolution <0.2 m/s | X | X | Elevating air speed which can offset the impact of increased room air temperature on occupants’ comfort |
| 2008 | Enthalpy estimation for thermal comfort and energy saving in air conditioning system [69] | Thermistors with accuracy to 0.5 °C temperature sensing + Humidity sensor for estimation Enthalpy | Optimum operative temperature for people during light, primarily sedentary activity | X | The least enthalpy estimator combines the concept of human thermal comfort with the theory enthalpy |
| 2010 | Task ambient conditioning system [70] | Thermo-camera with accuracy to 1 °C temperature sensing + wind velocity sensor with resolution to 0.5 m/s | Infra-Red images | X | A special air conditioning system heats only the feet and hands, and cools only the hands and face, to provide thermal comfort |
| 2010 | Air conditioning system of an AHU dedicated to the personalized ventilation system and an overhead fan-coil dedicated to control the room air temperature [71] | Thermistors with accuracy to 0.5 °C temperature sensing + Air flow rate sensor with resolution to 0.1 m3/s | X | X | Microclimate control by an individually controlled air distribution system aimed at improving the quality of inhaled air and thermal comfort off each occupant |
| 2010 | Campus air conditioning system managed by control center on internet [72] | RTDs with accuracy to 0.01 °C temperature sensing | Scheduled time-of-day | X | Scheduled control for energy saving |
| 2010 | Ceiling mounted personalized ventilation system [73] | Thermistors with accuracy to 0.5 °C temperature sensing + Air flow rate sensor with resolution to 1 L/s | PIR sensor | X | Using desk fans for providing convection cooling to each occupant in rooms |
| 2011 | Air conditioning system in conveniences stores in Taiwan [74] | IC type temperature sensor + embedded system for constructing a WSN | Digital camera | Digital power meter | WSN provides feedback of distributed thermal comfort index and controls environment |
| 2011 | Chilled ceiling and displacement ventilation aided with personalized evaporative cooler [75] | Thermistors with accuracy to 0.5 °C temperature sensing + Air flow rate sensor with resolution to 0.1 L/s + Humidity sensor | Personal location service | X | Personalized air conditioning directly towards the occupant trunk and face |
| 2011 | Air conditioning system strategies for energy conservation in commercial buildings in Saudi Abraia [76] | Thermostat based on thermistor | Specified schedules | X | Air conditioning model verification, investigation of energy savings and thermal comfort |
| 2013 | Personalized air condition and desk fan control for the convection flow around occupants [77] | Temperature sensor with accuracy to 0.01 °C + Thermal radiation sensor + wind velocity sensor with resolution to 0.1 m/s | Skin and core temperature; Sensible and latent heat; Clothing properties; Human metabolic | X | Building three models: CFD model; Thermal comfort model; Multi-segmental bio-heat model |
| 2013 | A versatile energy management system for large integrated cooling systems [78] | Thermistors with accuracy to 0.5 °C temperature sensing + Ambient property sensor | X | Level sensor | Versatile energy management platform for energy saving control of four large cooling systems |
| 2013 | A low-mixing ceiling mounted personalized air conditioning system [79] | Thermistors with accuracy to 0.5 °C temperature sensing + Air flow rate sensor with resolution to 0.1 L/s | Location based service | CO2 sensor | CFD, bio-heat, and comfort model coupling |
| 2014 | Variable air volume air conditioning system for buildings with large number of zones [80] | Thermostat based on thermistor | Calendar for occupancy prediction | X | Model predictive control |
| 2014 | Smart sensors enabled smart air condition control [42] | IC type temperature sensor | PIR detector, mobile phone and wearable device | X | Wearable sensing for smart control |
| 2015 | Supervisory control methodology for air condition system of commercial buildings [81] | Thermistors with accuracy to 0.5 °C temperature sensing | X | Electricity frequency detector | Air conditioning control to electricity grid integration |
| 2016 | Indoor air quality and energy management through real-time sensing in commercial buildings [82] | Thermistors with accuracy to 0.5 °C temperature sensing + Humidity sensor | Occupancy/movement detecting system through Wifi, GSM or Bluetooth signals, or through volume recognition with depth sensors (Ultrasound sensor) | Digital power meter | CFD, bio-heat, and comfort model coupling |
| 2016 | Multi-evaporator system integrated with networked control systems in large spatially distributed plants [83] | IC type temperature sensor + Embedded system for constructing a WSAN (Wireless sensor and actuators network) | Evaporator assembled near crowds in many places | X | Completing a detailed analysis of the end-to-end real-time flows over WSAN and a real-time kernel with an earliest deadline first (EDF) scheduler |