[Equest-users] 90.1 Supply Fan Energy

[Joe Fleming]

I have personally never seen fan power equal the total of cooling and
heating power, except in certain climate zones where an economizer can
run often or when the exhaust/ventilation fan power, not associated with
cooling/heating, is high.
Not sure if you are stilling looking for help here.  
What does your fan schedule look like?  Is your fan set to run 24 hrs?
What climate zone are you in?  What are your space cooling and heating
temperature set-points?
 
-----Original Message-----
From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of M.
Shields
Sent: Wednesday, April 06, 2011 3:22 PM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] 90.1 Supply Fan Energy
 
Hi all,
 
I am in the process of breaking out the fan energy from my HVAC system
per ASHRAE 2004 G3.1.2.1, following G3.1.2.9.  The amount of energy
coming from my fans seems massive and I'm not sure if that is typical,
or if I've messed something up.  I started by setting the temperature
difference of 20 degrees between supply and desired temp (55/75 cooling
and 90/70 for heating) and specified 62.1-2004 ventilation for outside
air.  I then ran equest and used the SV-A reports to get supply CFM for
each system.  From that number I then used Table G3.1.2.9 to get BHP for
each system, which I then converted to kW using the formula in ASHRAE.
I then took that number and divided by CFM to get kw/CFM and entered
this number on the system->fan tab.  When I go to the SV-A report the
system kW is exactly what I calculated it to be, but the energy required
for my ventilation fans is about the same as my heating and cooling load
combined, which seems outrageous.  
 
Is this typical?  Have I entered it In the wrong way? I would think fan
consumption would typically be a fraction of the actually heating and
cooling energy.  Thanks for any thoughts.
 
____________________________
Michael Shields
Facility Strategies Group, LLC
1012 Market Street, Suite 307
Fort Mill, SC 29708
Phone: 803-493-4507
Fax: 803-548-2511
Email: mshields at fstrategies.com
 
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