[Bldg-sim] epact 179d fan power

[Patrick J. O'Leary, Jr.]

per the 179d guidelines use the 2001 fan power allowance.  remember your 
actual tax building model (i.e. proposed in the leed world) is supposed 
to reflect actually site measured power consumed by the units.  i.e. 
volts x amps x pf (pf = power factor).  (or volts x amps x pf x sqrt(3) 
for 3 phase equipment).  the reality is that the fan will be using less 
power than the nameplate or catalog (good for your simulation savings) 
but the kicker is trying to find the pf values for motors.

On 3/8/13 4:23 PM, Steve Jacobs wrote:
>
> I have a question about the fan power calculation used for 2001 epact 
> models.
>
> The NREL guidelines say to use the 2001 fan power allowance instead of 
> appendix G. However, the 2001 guidelines are only for nameplate 
> horsepower. The nameplate requirements are actually the same in 2001 
> and 2004.
>
> COMNET says to use the formula bhp = nhp * eff_motor, then fan power 
> (watts) = (bhp * 746)/eff_motor
>
> This comes out to fan power(watts) = nhp * 746
>
> This doesn't seem to make sense to me. What have you guys been using 
> for fan power?
>
> -Steve
>
>
>
> _______________________________________________
> Bldg-sim mailing list
> http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
> To unsubscribe from this mailing list send  a blank message toBLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20130313/f96d96c0/attachment-0002.htm>