A dry temperature efficiency of 85 per cent is equivalent to a wet temperature efficiency of over 90 per cent. The wet temperature efficiency is theoretical and may not work in practice due to freezing. We have tried to illustrate this in the diagram below.
Temperature efficiency
Energy recovery, counter-flow heat exchanger
Do not be misled by various "marketing tricks" that specify different efficiencies for the same heat exchanger.
We always specify the dry efficiency, which is also the only efficiency that can be measured during an inspection.