Uncertain about cooling req.
Uncertain about cooling req.
(OP)
Hi.
I need to replace an air conditioning unit for an MCC room. Currently there is a 10 ton unit and it cools sufficiently. The fins are corroding, etc.
I have calculated the area of the room at approx. 23 ft2
I have transformers with the following kVA rating..
45, 1250, 1250, 15, 50, 30, 45, 1250, 1250, 150.
The heat output for no load on the transformers I got from a table at 14000 watts.
I guessed the change in temp. to be 20 deg. F.
Using the equation:
(watts * 3.413) + (1.25 * 23ft2 * 20deg F) = 48357 Btu/hr
48357/12000 = 4 tons of cooling.
If I do the same calculation with a heat loss with a 50% load I get 13 tons of cooling.
What am I doing wrong. This doesn't seem correct because a 10 ton unit is keeping the room cool.
Thank you
I need to replace an air conditioning unit for an MCC room. Currently there is a 10 ton unit and it cools sufficiently. The fins are corroding, etc.
I have calculated the area of the room at approx. 23 ft2
I have transformers with the following kVA rating..
45, 1250, 1250, 15, 50, 30, 45, 1250, 1250, 150.
The heat output for no load on the transformers I got from a table at 14000 watts.
I guessed the change in temp. to be 20 deg. F.
Using the equation:
(watts * 3.413) + (1.25 * 23ft2 * 20deg F) = 48357 Btu/hr
48357/12000 = 4 tons of cooling.
If I do the same calculation with a heat loss with a 50% load I get 13 tons of cooling.
What am I doing wrong. This doesn't seem correct because a 10 ton unit is keeping the room cool.
Thank you





RE: Uncertain about cooling req.
RE: Uncertain about cooling req.
So your motivation to change from what works is...
RE: Uncertain about cooling req.
When I make a recommendation for replacement, I need to justify it.
The more I looked into the heat load, the more it appears that the 10 ton isn't sufficient but subjectively it seems to work
RE: Uncertain about cooling req.
Good on ya,
Goober Dave
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RE: Uncertain about cooling req.
RE: Uncertain about cooling req.
what does 1.25 mean?