TFS · Supporting topics · Problem 13PDFSolution in PDF ↓
TFS · Supporting topics · Problem 13
Problem & Solution
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- Problem: 90 degree 20% relative humidity air is cooled using a 75% effective evaporative cooler.
- Approach: So the formula for an evaporative cooler or the effectiveness of an evaporative cooler can be found in the reference handbook and it says that the effectiveness of an evaporative c...
- Key values: 20 %, 75 %, 100 %
- Reference: reference handbook, look up
- Result: We can get T2 by itself and that equals 69.6 degrees F.
- ✅ Answer: C
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Student questions asked in live office hours about this problem
OH 103
Q: In the TFS reference handbook equation for evaporative cooler effectiveness, why is the 100 neglected in the solution even though it appears in the equation?
A: The 100 isn't an error—it's there to convert the result to a percentage. If you calculate effectiveness as 0.6 without the 100, multiplying by 100 gives you 60% effectiveness. The handbook includes it for convenience so you don't forget to convert to percentage form.