HVAC · Practice-Exam-2 · Problem 44PDFSolution in PDF ↓
HVAC · Practice-Exam-2 · Problem 44
Problem & Solution
Video Synthesis
Problem: A 75% efficient fuel pump supplies 50GPM of number 2 diesel fuel with specific gravity 0.88.
Approach: So to find the electrical demand we're going to find the hydraulic horsepower or water horsepower and then we'll apply the efficiencies which we have ...
Key step: The differential pressure across the pump is 30 psi.
Watch out: So if it's water then you don't need the S G because specific gravity of water is 1 so across that out and these two become equivalent because the onl...
Result: So that is the input electrical demand to run the motor that drives the pump best and the answer choice is B.
✅ Answer: B
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Student questions asked in live office hours about this problem
OH 102: HVAC: Full Practice Exam #44
Q: Why is it that when the pumping power equation using the specific gravity is used for the solution?
A: So I would love to see your work both ways. I'm seeing this. This bothered me.