AC question

[piru]

let me know how to find the answers

[Admin]

I'm not 100% sure I'm right.

We use a Psychrometric Chart to solve this problem.

A Dry Bulb of 90F and a Dew Point of 70F would give us a Wet Bulb of 75.6F, a Relative Humidity of 52% and Enthalpy of 39.55 BTU/lb.

A Dry Bulb of 65F and a Dew Point of 58F would give us a Wet Bulb of 60.6F, a Relative Humidity of 78.1% and Enthalpy of 26.8 BTU/lb.

39.55 BTU/lb - 26.8 BTU/lb = 12.75 BTU/lb.

I attached a copy of the Psychrometric Chart I used.  Hopefully it makes sense, it's been 20 years since I used one 

[Porcupinepuffer]

The psychrometric chart I used is different, but I got 12.6 btu/lb. Mine has the wb and dp temperatures on the left side and uses the horizontal lines for dp numbers and wb lines are angled downward.

[Admin]

Yes I believe all his available answers are wrong.  The enthalpy for a DB of 90F and DP of 70F is actually 38.95 BTU/lb.

38.95 - 26.87 = 12.08 BTU/lb.

We all seem to be in the same ballpark.  It might be one of those, pick the most correct answers.