Dear All,
For a university classroom/studio building I'm modeling for LEED EAp2/c1
under the 2009 version:
The proposed design has two AHUs connected to 23 VAV terminal units and 14
Constant Volume terminal units, all with HW loop reheat from an electric
boiler. The baseline system is System number 8 per Appendix G, VAV with PFP
boxes, with eletric resistance reheat. The waterside of cooling is
purchased chilled water in both cases.
Question 1: In the proposed design, I'm approximating the constant volume
terminal units via a minimum flow ratio setting of 1.0. Is this the best
way to do it?
Question 2: What is the equivalent of this in the Baseline design per
Appendix G? If I repeat the same method used in the proposed design, should
I let the terminal Primary CFMs default to auto-sizing? The Baseline
auto-sized CFMs are lower than what is being specified in the mechanical
design for the proposed model, working to my disadvantage.
Thank you,
Ramana Koti.
1. Sounds logical - although - why can't you specify a reheat fan system instead of a VAV system - that's probably the more appropriate system type. I'm assuming the constant volume systems are being fed by a separate AHU.
2. If your baseline is auto sizing less than your proposed design - I would question the volume of air being designed in. Either that or maybe there is a load designed that's not being represented in the model?
Vikram Sami, LEED AP BD+C
Vikram,
Thanks for your response. Each AHU contains a mixture of CV and VAV
terminal units. I'm double checking the loads currently.
Ramana.