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In case of sensible heating of air, the coil efficiency is given by (where B.P.F. = Bypass factor)
B.P.F. - 1
1 - B. P.F.
1/ B.P.F.
1 + B.P.F.
B.P.F. - 1
1 - B. P.F.
1/ B.P.F.
1 + B.P.F.