Person & Presence Detection

Intelligent or smart HVAC control is one important application for low-cost infrared arrays like our 32x32 thermopile array. The sensor can detect the occupancy of a room. The number of people can be obtained from the thermal sensor. This data is then used to calculate the required heating and cooling with respect to the number of people, desired room temperature and outside temperature. If there are many people in a room, extra heating in the winter might not be necessary. On the other hand on a hot summer day, the cooling level should probably be increased. In contrast to normal room thermostats, an intelligent system can anticipate the required heating and cooling. This will result in less overshoot in contrast to a conventional room thermometer which reacts more slowlty to room temperature variations resulting in longer time constants. The usage of thermopile arrays for smart HVAC control can drastically reduce the energy consumption of a building.

In addition to energy savings, the level of comfort can also be increased. As the location of all people in a room can be obtained from the infrared array, the direction of the air conditioner ventilation can be controlled in such a way that no one is in the draught. The further increase the comfort, the intelligent HVAC can be combined with an air quality monitoring system for CO2, which can be realized with single or dual thermopile sensors and sensor modules.

To have an overview of the room, choose a sensor with large field of view of 90 degree or more. The required spatial resolution of the sensor depends on the room's size and height. For most rooms, the 32x32 thermopile array is sufficient, while in large rooms with high ceilings as they can be found in many public buildings, the higher resolution 80x64 array is the better choice.

People all around the world are living longer. Especially in western societies, many people prefer to live in their own home as long as possible instead of a nursing home or assisted living. This creates a dilemma for the caregivers and relatives. On one hand the caregivers and relatives want to be sure that everything is fine and on the other hand they cannot be present at all time.

One emerging solution are elderly monitoring systems. There is a large choice now available in the market. Most require the elderly person to push a button in case of need.

The use of a low spatial resolution infrared thermopile array can solve many challenges induced by elders living on their own. It can be used to keep track of their location inside their home. At the same time their privacy is respected due to the low spatial resolution of the thermal sensor. Additionally, the sensor can be used to detect a fallen person and notify caregivers and relatives or release an alarm. Unusual situations can be monitored, for example if the person stays for unusual time at the same location. Further capabilities are fire detection and intrusion alarm, which can also be implemented with the same sensor. In case of dementia or Alzheimer's, a notification can be released if the person leaves an area. This enables the person to stay maximally independent, while easing their caregiver's and relative's stress.