The air curtains are used in entrances of buildings with highly intensity of traffic where the interior is at risk of cooling down when doors are open.
The duct heaters are applicable in several duct heating solutions. They can work as a separate element which heats the room through direct operation or be a component of a duct system, e.g. associated with the heat recovery units.
As a preliminary heater, it heats up the air of a negative temperature in order to prevent the exchanger from freezing in the unit.
It can also perform functions of the secondary heater, which, immediately following the exchange of heat in the heater, heats the air diffused into the rooms up to the desired temperature.