ASRAE 90.1 fan power broken up

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Dear All,

I have a comment from the USGBC that the fan power for each individual HVAC
system be determined using the fan supply volume for that specific HVAC
system as determined from Section G3.1.2.8. and *that fan power* must then
be broken up into supply, return, exhaust, and relief.

is this mean , for example , if I have a system with the following
specifications :
Supply 69,482 CFM
Return 58,003 CFM ( 83.5% of the supply)
OSA= 11,479 CFM (16.5% of supply)

and the total fan power using section G3.1.2.8 is 85 KW (Calculated using
the supply volume).

what is the value for the return fan in this case?

So the braken up will be

Mohammad Almasri's picture
Joined: 2011-09-30
Reputation: 400

Hi all,

Can seem to find the scrolls under the drop down menu.
What I'm missing here-have they been taken out of the equest?


[cid:image001.png at 01CBAD85.80C8CCD0]

Nikola Kravik2's picture
Joined: 2011-09-30
Reputation: 0


If I am not mistaken, there has never been a scroll chiller type in this dialog box.

Demba Ndiaye's picture
Joined: 2011-09-30
Reputation: 200

Screw and Scroll are both Rotary type chillers. Go with the Electric Screw option.

Joe Fleming

Fleming, Joe's picture
Joined: 2011-09-30
Reputation: 0

There are performance curves available for scroll chillers, but no scroll chiller type (I don't know why). You can select a screw chiller, as Joe suggested, and then manually change the performance curves.

Kelsey Van Tassel

Kelsey VanTassel's picture
Joined: 2011-09-30
Reputation: 0