Which should be prioritized :
Heat exchanger efficiency or SFP ?

It is common to see specifications including requirements for high heat exchanger efficiency, for example, above 80% for rotary wheel exchangers, while simultaneously imposing low SFPs, around 0.30 W/(m³/h) per air stream.

This contradiction can be explained by the fact that achieving a higher heat exchanger efficiency leads to an increased pressure drop (ΔP), which in turn requires more power to compensate for this loss.

Consequently, this results in a higher SFP.

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On our MCX units, several pitch options are available (for both rotary and plate-type exchangers), allowing optimization of either the SFP, the efficiency, or a compromise between the two with an intermediate pitch—but as the saying goes, no one can achieve the impossible.