PIR thermostat control for heating loads

Danlers Limited design and manufacture a range of HVAC controls, including a passive infra-red thermostat for heating loads.
The product (pictured) combines an adjustable room thermostat with a passive infra-red person detector. If somebody is present in the room, the heating unit is switched on to achieve the selected thermostat temperature. When nobody is present the temperature is allowed to fall to a set-back temperature.
This gives comfortable temperature control while reducing energy consumption by restricting the time when the heating unit is working. The user is not paying to heat an empty room when unnecessary.