TeFo recuperator (heat recovery unit)
has a bank of heat exchange tubes placed in the tube body and ventilators (fans) which provide for discharge of indoor air and delivery of fresh air. Two air flows (those of discharged and incoming air) move in TeFo recuperator towards each other where one air flow moves inside the tubes, the other outside the tubes. During this countercurrent flow one current gives the other heat energy through the separating tube plates. In winter hot air which is discharged from inside gives up heat, in summer discharged air with lower temperature than outside air gives up cold. As the result outside air is getting inside quite warmed up in winter or cooled down in summer and it happens practically without additional energy (ventilation power consumption is too insignificant if compared to the amount of warm air saved during winter months and cool air saved during summer months).
There are many mounting options for TeFo recuperators on a wall, in a wall niche, hidden inside a wall, etc. Each of them ensures high energy saving ratio, heat comfort in a room and high air flow rate.
Some basic installation shemes: