By taking into account enthalpy, you're measuring the latent heat content (due to the moisture in the air) as well as the sensible heat. This would be the total work done by the coil.

Substitute the delta T for the humidity ratio difference (kg water/kg dry air).
You would still need to use the return air and the supply air enthalpy values to calculate this.

The formula needs 2 temperatures across the coil to work, before and after.