Heat Generated form Electrical Equipment 1

[AnEngineer]

Could someone please help me with the following calculation:

How do I calculate the heat generated by the following electrical equipment:

a) 2 x UPS units each running at an electrical load of 4kW
b) 2 x UPS units each running at an electrical load of 4kW
c) 2 x UPS units each running at an electrical load of 2kW
d) Transformer running at an electrical load of 20kW
e) Transformer running at an electrical load of 20kW

With what co-efficient the total load shall be multiplied to get the amount of heat generated?

Consider power factor for transformer as 0.85 ad UPS 1.

 

[MintJulep]

UPS manufacturers appear to be very good at providing heat output figures on their data sheets. Contact the maker.

 

[lilliput1]

Space heat gain from transformers, UPS & pumps typically fall in the category of "Motor in, driven equipment out". For this case the heat gain to the space=

Qs Btu/hr = (1/E-1)xKWx3413

Where E = efficiency in decimals=output/input

You have to check the manufacturer's efficiency ratings at full & part load. The larger capacity units are more efficient.

A 2nd cases of heat gain category is "Motor out, driven equipment in" for which Qs=KWx3413

A 3rd case of heat gain category is "Motor in, driven equipment in" for which Qs=KWx3413/E

 

[DRWeig]

Howdy AnEngineer,

Good answers above. You really need to check with the UPS manufacturer to find waste heat numbers, they can vary a lot. Transformers will be less than one percent if they're loaded well.

However, I have a suspicion from the way you worded your question that this may be an existing installation (tell me if I'm wrong), which brings up my favorite engineering rule: Never calculate anything you can measure. If you can measure the watts on the feeder that drives all this equipment, you'll have a really good answer. It all turns to heat in the room where it's used (unless a load is a fan that exhausts somehow).

Let us know what you figure out!

Thanks tons,

Old Dave

 

[AnEngineer]

Lilliput1: Thank You. I have used your formula for estimation.

DrWeig: It's for a new installation. Thank you.