Psychrometrics: sensible heat factor for cooling and dehumidification For a process over a cooling coil, with h1 = enthalpy of entering air, h2 = enthalpy of leaving air, and hA = enthalpy at the end of dehumidification (apparatus dew point), choose the correct expression for the sensible heat factor (SHF).

Given data

• h₁: enthalpy of entering air
• h₂: enthalpy of leaving air
• h_A: enthalpy at apparatus dew-point (end of dehumidification line)

Concept/Approach
For cooling and dehumidification, the sensible heat factor is the ratio of sensible heat to total heat for the 1→2 process and, in terms of psychrometric geometry, is given by the segment ratio along the process line.

Derivation (sketch-based reasoning)
Total heat removed = (h₁ − h₂); sensible component corresponds to (h₁ − h_A).
SHF = (h₁ − h_A) / (h₁ − h₂).

Sanity check
If there is no dehumidification, h_A → h₂ and SHF → 1, as expected for purely sensible cooling.

Final Answer
SHF = (h1 − hA) / (h1 − h2)