The regulation limits the energy consumption of heat recovery systems by specifying a minimum heat recovery efficiency and the maximum specific current consumption of the fans SVLint limit.
The permissible pressure loss ∆pWRS required for the design of the heat recovery system is not directly apparent. This can, however, be calculated with the assumption of the fan efficiency ηfan (according to EU 327) and the filter pressure loss ∆pF (according to EUROVENT 4/21).
With the corresponding assumptions one obtains the relatively simple calculable/programmable formulas.
With the formulas 05 and 06, the permissible pressure drop ∆pWRS can be calculated for each nominal air flow qnom and displayed in a diagram.
Diagramm 1: Permissible pressure loss of the heat recovery system as a function of the volume flow