We are working on a laboratory building that will be pursuing LEED Core &
Shell. We are trying to confirm the modeling requirements for heat recovery
and laboratory supply airflow control. It appears that these two questions
are interrelated.

Based on Appendix G section 3.1.2.10, it appears that if we model heat
recovery in the proposed case, we will need to model it in the base building
also. (Note the building is in climate zone 5a) Can anyone please confirm
that lab heat recovery can not be counted as savings? It is my
understanding that this supersedes Section 6.5.6.1 discussion of energy
recovery, is this correct?

The core air handling units design supply and exhaust rates are based on 2.0
cfm/sf. The design team expects that the lab supply and exhaust will be
VAV, but since this is a Core & Shell design the minimum required flow rates
are unknown. Also, the potential for resetting air flow rates during
unoccupied hours is unknown. It is my understanding that baseline and
proposed models will need to assume the same supply and exhaust rates, but
is not clear what those flows should be. According to Section 6.5.7.2,
buildings with fume hood exhaust rates greater than 15,000 cfm (the building
under consideration) shall include at least one of the following:

(a) VAV Exhaust and Supply capable of minimum flows of 50% or less of
design.

(b) Will not be met...

(c) Heat recovery

What minimum supply and exhaust flow rates do we need to assume? Do we
assume that the flows are constant (24/7) at the design values? Or, do we
follow item A listed above?

Any insight into lab Core & Shell makeup/exhaust flow and/or heat recovery
modeling requirement is appreciated.

Thanks,

Mickey Bush