[Bldg-sim] Exhaust, outside air and infiltration for LEED

Michael Tillou michael.tillou at gmail.com
Fri Nov 7 11:53:14 PST 2008

You are correct that Appendix G requires outside air to be the same for both
as-designed and baseline models.  You would not be able to claim savings for
reduced ventilation airflow from a more efficient fume hood.   Similarly you
cannot claim credit for reduced ventilation airflow on displacement
ventilation and UFAD systems. 
However I see no reason why you wouldn't be able to claim the fan energy
savings associated with a more efficient fume hood.
Michael Tillou, PE, LEED
Tillou Engineering, LLC
Williamstown, MA 01267
P: 413-458-9870 C: 413-652-1087

From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Bishop, Bill
Sent: Friday, November 07, 2008 9:04 AM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] Exhaust, outside air and infiltration for LEED

The mechanical engineer for a campus laboratory building with 100% OA wants
to claim energy savings for reduced exhaust from more efficient fume hoods.
(Established design practice uses hoods with 100 fpm flow - they are
installing 70 fpm hoods. This reduces peak exhaust from 700 to 490 CFM per
hood.) My approach has always been to keep outside air, exhaust and
infiltration flows identical between the proposed and baseline models
(except for DCV). (This was not easy for this model with proposed VAV and
baseline constant volume packaged rooftops.)


Has anybody successfully claimed OA/exhaust/infiltration savings for a LEED





William Bishop, EIT, LEEDR AP | Pathfinder Engineers LLP

Mechanical Engineer


3300 Monroe Ave., Suite 306 
Rochester, NY  14618

TEL (585) 218-0730 Ext. 114
FAX (585) 218-0737 

bbishop at pathfinderengineers.com



P Please consider the environment before printing this email


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