Referring to the illustrated psychrometric chart, suppose air at a dry-bulb temperature of 60oF and a relative humidity of 52% passes over a heating coil, resulting in sensible heat gain, and the off-coil temperature is now 80oF. What is off-coil relative humidity? Illustration GS-RA-22

Illustration GS-RA-22: the U.S. Coast Guard has not released this illustration.

Question

Referring to the illustrated psychrometric chart, suppose air at a dry-bulb temperature of 60oF and a relative humidity of 52% passes over a heating coil, resulting in sensible heat gain, and the off-coil temperature is now 80oF. What is off-coil relative humidity? Illustration GS-RA-22

Illustration GS-RA-22: the U.S. Coast Guard has not released this illustration.

Accepted Answer

Option B: 27%. Adding sensible heat moves the psychrometric state horizontally right to 80°F, increasing moisture capacity and lowering relative humidity down to approximately 27%.