eQUEST users,
I am modeling a simple 9 story office building in v3.63. The system type is
VAV w/ HW Reheat. One Fan system per floor.
With a 20F Zone Reheat Delta-T the Annual Energy Consumption is 38% higher
than it is with a 30F Zone Reheat Delta-T.
This is not intuitive to me why the energy use greatly increases with a
lower zone reheat Delta-T.
Thanks for any help,
Dennis Hunt
one think I can think of is - there might be more unmet heating hours
in the first case.
Dennis,
The first thing you should look at anytime you are analyzing the
difference in energy use is your BEPS/BEPU reports. Is the difference in
heating, cooling, fan energy, pumping? As R B said, is there a
difference in unmet hours?
For VAV-specific design/energy issues, check out this free resource:
http://www.energydesignresources.com/Technology/HVACDesign/tabid/97/arti
cleType/ArticleView/articleId/331/Default.aspx
Regards,
William Bishop, EIT, LEED(r) AP
Thanks Bill, RB for your input,
I looked at the BEPS and found Heating, cooling, Vent Fans, Pump&Aux all
went up for the 20F Zone Reheat Delta-T.
Hours coincident Cool-Heat Load and Fan electric During Heat & Cool jumped
significantly. Any thoughts on this?
No unmet hours for either case
Thanks,
Dennis