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defining equipment loads

asked 2017-10-26 09:30:59 -0500

Yael's avatar

updated 2017-11-10 08:06:29 -0500

I would like to model a computer room in which every occupant uses 1 computer. I have a schedule for the occupancy and I wish to correlate the equipment load to it. Should I use a multiplier and how?

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answered 2017-10-26 10:47:19 -0500

updated 2017-10-26 10:59:50 -0500

If you want to maintain a 1:1 ratio of occupants to computers, then the occupancy schedule and computer room schedule should be the same. When you define the occupant and equipment objects in the model, you set a peak usage value and reference a schedule that is just multiplied with that peak usage value. This can be defined as either a total value ($occupants, W, etc.$) or as a per-floor-area value ($occupants/ft^2, W/ft^2, etc.$). Using either method, you should set the peak computer electricity use equal to the power draw of one computer [$W / person$] multiplied by the peak occupant use.

Let's say that the computer room is 1,000 $ft^2$, has 20 seats, and each computer uses 100 $W$. When you define the occupant object, the peak total occupant count is 20 $people$. When you define the equipment object for the computers, the peak electricity use is 2,000 $W$ (20 $people$ * 100 $W/person$).

If you are defining the peak occupancy with a per-floor-area value, which is most common, then the occupant density is 20 $people$ / 1,000 $ft^2$ = 0.02 $people / ft^2$, and the equipment power density is 2,000 $W$ / 1,000 $ft^2$ = 2 $W / ft^2$. This would be the same as taking 0.02 $people / ft^2$ * 100 $W / person$ = 2 $W / ft^2$.

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Thank you very much!

Yael's avatar Yael  ( 2017-10-26 12:23:28 -0500 )edit

You're welcome! If you're satisfied with the answer, let others on the site know by clicking on the check mark button to the left of the answer.

Aaron Boranian's avatar Aaron Boranian  ( 2017-10-26 12:33:59 -0500 )edit

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Asked: 2017-10-26 09:30:59 -0500

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Last updated: Oct 26 '17