The supply cfm reported in SV-A is corrected for altitude, but the fan
power on the same report is for sea level. So if, for example, you enter
0.0003 kW/cfm for Appendix G Baseline System 1 and 2 fan power, the SV-A
reported fan power is low relative to the SV-A flow rate. (This was
noticed in a LEED review and I was asked to verify the fan power
calculations.)
Can/should I be multiplying the baseline fan power allowance by the
altitude factor (also reported on SV-A)?
Thanks,
Bill
Hey Bill,
These altitude shenanigans eQuest likes to play in the airflow/coil
calculations are a potentially messy issue when it comes to baseline
calcs and LEED reviewers.
Attached thread pretty much covers the issue inside and out from
multiple perspectives.
There are a 2 schools of thought:
1. Set project altitude to '0' - this corrects all airflows, but
you'll find coil capacities are sized slightly differently (this has
been a working approach for LEED reviewers in my experience)...
2. Divide all entered airflows by the altitude factor for the
project (listed on those system reports). A more cumbersome solution,
but I gather this will correctly trick eQuest into doing the intuitive
thing with regard to airflow/coil sizing.
My sense is this is one of those things fundamental to DOE-2 that won't
easily change, but I've said before - it would be a great 'feature' to
add in future releases to have an option to treat all entered capacities
are relative to the site elevation, instead of sea level.
~Nick
NICK CATON, E.I.T.
Nick,
Thanks for forwarding the previous post - I should've searched the
archives first.
I see merits to both schools of thought. My preference for now will be
to set project altitude to zero. The air flow and fan power reported in
SV-A will be consistent with the calculated/entered value for baseline
fan power (in kW/cfm).
Bill