[BLDG-SIM] New Calculation method for Baseline Fan Energy in Addendum R

[Michael Rosenberg]

Mike and Andrew,

That is Addendum R that Andrew is referring to. It is actually Addendum R to 90.1, 2007. Even though 2007 has not been published yet, ASHRAE is already up to Addendum R. As for the calculation, Andrew made a good catch. It is a typo and should read   CFM x 0.00094 + A  and CFM x 0.0013 + A.

Mike 


Michael Rosenberg
Oregon Department of Energy
625 Marion St. N.E.
Salem, OR 97301-3742
Phone : (503) 373-7809
Fax: (503) 373-7806

>>> "Michael Tillou" <michael.tillou at gmail.com> 10/24/2007 11:39:01 AM >>>
I think you mean to be referencing ASHRAE 90.1-2004 addendum ac not addendum
r which includes two new methods for calculating fan power limits.  The
first looks at total Motor HP which isn't very useful for energy modeling
purposes and the second looks at fan brake-horsepower.  The fan
brake-horsepower equations are "(CFM x 0.00094) + A"  and "(CFM x 0.0013) +
A" for constant volume and variable volume systems respectively.  CFM is the
design airflow rate and A is the brakehorse power adjustement for various
pressure drop adjustments given in Table 6.5.3.1.1B.
 
Mike
 
Michael Tillou, PE, LEED
Tillou Engineering, LLC
Williamstown, MA 01267
P: 413-458-9870 C: 413-652-1087


  _____  

From: BLDG-SIM at gard.com [mailto:BLDG-SIM at gard.com] On Behalf Of Andrew Craig
Sent: Wednesday, October 24, 2007 11:56 AM
To: BLDG-SIM at gard.com 
Subject: [BLDG-SIM] New Calculation method for Baseline Fan Energy in
Addendum R



 

I was wondering if anyone out there can explain the new calculation shown
for baseline fan brake horsepower in Table G3.1.2.9 of Addendum R to ASHRAE
90.1-2004?  At first glance, the equation doesn't make sense because you are
subtracting a relatively small number (0.0013+A) from a large number (CFMs)
leaving you with a ridiculously large baseline fan motor brake horsepower.
Am I just reading this wrong or is there a typo?  Isn't there an easier way
out there to calculate baseline fan energy (please see version 1 of Appendix
G for another confusing calculation)?

Andrew Craig, EIT, LEEDR AP | Mechanical Designer

INTERFACE ENGINEERING 
708 SW Third Avenue | Suite 400 | Portland, OR 97204 

direct: 503.382.2696
office: 503.382.2266
fax: 503.382.2262
email: Andrew_C at ieice.com 
web: www.ieice.com 

Consultants of Choice to the Built Environment for over 35 years
Kirkland, WA | Portland, OR | Sacramento, CA | Salem, OR | SanFrancisco, CA

 



==================

You received this e-mail because you are subscribed 

to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 

from this mailing list send a blank message to 

BLDG-SIM-UNSUBSCRIBE at GARD.COM 


======================================================
You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 
BLDG-SIM-UNSUBSCRIBE at GARD.COM


===========================
You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 
BLDG-SIM-UNSUBSCRIBE at GARD.COM