Nevertheless, a part of the latent heat of humid extract air can also be used in the plate heat exchanger due to condensation. This has a variety of effects, for
example, heat transfer is improved.
A possible increase in pressure loss due to water drops caused by condensation or a water film in the area of exhaust air must be taken into
account during the design process; this may well account for up to 50 % of the value in dry operation.
Under extreme conditions, i.e. at very low outside temperatures, the condensate produced – starting at the cold corner – can freeze and thus possibly
put the heat recovery unit out of operation. When designing, the relevant manufacturer's information on this subject should be taken into account.
Some considerations have also be taken into account while constructing:
In ventilation units, it is important that the condensate produced is separated from the air stream, collected and discharged. In order to avoid the transfer of condensate from the extract air to the supply air, a pressure drop towards the extract air should be planned in addition to a tight design. Special measures are required for "horizontal installation" (= horizontal plates), as the condensate drains off uncontrolled.
In ventilation units, it is important that the condensate produced is separated from the air stream, collected and discharged. In order to avoid the transfer of condensate from the extract air to the supply air, a pressure drop towards the extract air should be planned in addition to a tight design. Special measures are required for "horizontal installation" (= horizontal plates), as the condensate drains off uncontrolled.