Naber 4043064, backflow valve Thermobox, heat recovery system, diameter: 150 mm

• Backflow valve Thermobox.

Thermobox 150, black/silver. Heat retention system Thermobox for retrofitting existing Naber wall boxes and for vertical installation (air duct over the roof). The heat recovery system Thermobox consists of three flap pairs with magnetic closure arranged behind each other in defined distance. With a U-value of 2.2 W/(m²K), Thermobox clearly stands out from conventional wall boxes (approx.25 W/(m²K)) and achieves an insulating effect comparable to that of insulated glazed windows. In a closed system, two completely insulated air chambers are formed. A reflective layer on the inward facing first pair of dampers reduces the transmittance at the inlet of the system and thus prevents additional heat losses. On the other hand, conventional wall boxes have simple backflow flaps that are not suitable for installation in the wall façade of energy-efficient or energy-refurbished house types due to their lack of thermal insulation properties.