[Equest-users] 90.1 Supply Fan Energy

[M. Shields]

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:  <mailto:mshields at fstrategies.com> mshields at fstrategies.com

 

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