[Equest-users] Chemistry Laboratory Model

[Paul Erickson]

I'd like to add to Vikram's comment about CAV hoods.  I'd encourage you to advocate for VAV hoods if the zone's hood CFM is 2ACH or greater.  There has been a lot of progress in recent years in working towards lower occupied and unoccupied ACH minimums, and 2 ACH may be within reason for many clients in the coming years.  If VAV hoods are in place, and the capabilities of the air valves allow, the system would be able to turn down to a lower ACH minimum and garner your client savings.

Paul

Paul Erickson  LEED(r) AP
Sustainable Practice Leader



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From: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Vikram Sami
Sent: Monday, December 07, 2009 11:51 AM
To: Kugler, Nicholas; equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] Chemistry Laboratory Model

Nick,
The way I would approach this:


1.       Establish what the minimum flow rate for each hood is (as a percentage of maximum). Most chemical hoods have a minimum required cfm rate even when closed that flows through the reagent shelf below to keep it ventilated.

2.       Establish a diversity schedule for the hoods

3.       In eQUEST v3.63 and above you can specify airflow tracking for exhaust air streams on a thermal zone basis - there's a good help section on what the different tracking options do. It's my understanding that this was put in specifically for fumehoods. Set your max flow rate here and set up a fraction schedule to determine flow rate.

One thing you might want to check up on is the fumehood density. If the lab is very fumehood intensive, then it might make sense to go with the VAV hoods. However, if it's a ventilation driven lab (as opposed to an exhaust driven lab), you might as well have constant volume hoods.

For instance, if your EHS requires 6 air changes per hour in a 10 foot high 10,000ft2 lab, your supply cfm = 10,000 cfm. Lets say you have 10 x 6' wide fumehoods with 800cfm at max sash height (18"). That would give you 8,000 cfm. So having VAV controls on the hoods is not going to reduce your airflow unless you ramp down to below 5ACH during unoccupied hours.

Hope this helps
Vikram Sami, LEED AP
Direct Phone 404-253-1466 | Direct Fax 404-253-1366
LORD, AECK & SARGENT ARCHITECTURE

From: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Kugler, Nicholas
Sent: Monday, December 07, 2009 7:42 AM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] Chemistry Laboratory Model

I am about to begin an energy model for a large university lab project that includes about 150 VAV chemical fume hoods. The building systems will include a true VAV exhaust system, not a bypass system. Please advise how this can be modeled using eQuest. Thank you in advance.

Nick Kugler, LEED AP
Mechanical Engineering

TLC Engineering for Architecture
Your Architecture 2030 Partner

874 Dixon Boulevard
Cocoa, FL 32922

phone:

321-636-0274

fax:

321-639-8986

website:

www.tlc-engineers.com<http://www.tlc-engineers.com>


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