Hi All,
In Florida, we are constantly dealing with the Natural Ventilation section in ASHRAE 62.1-2007. We consistently have significant issues with confusion on the part of project teams on this subject. In my opinion, the USGBC has not done a great job clarifying this in general and offering some guidelines on what compliance paths will and won't be accepted. Their guidance is buried in CIRs that are usually project specific, and can be a bit confusing and rambling. Fortunately much of this is cleared up in future versions!
To try to guide our teams better I have prepared the following notes. I see these questions pop up on this forum a lot too, so I wanted to share it here as well. Of course, if I have misinterpreted anything as well, please offer me some feedback and discussion.
http://www.joesnider.com/guide-to-ashrae-62-1-2007-and-natural-ventilati...
Best regards,
Joe Snider
Jason Biondi
Managing DirectorEnergy Cost Solutions Group
17 thumbs up
June 9, 2014 - 5:11 pm
Hi Joe. Thanks for the post. Have you had experience with the 2010 version of 62.1? Specifically will direct kitchen exhaust be required for multi family, hot/humid, mid rise pursuing the natural ventilation approach to compliance with IEQ Ventilation prereq.?
Best regards
Jason
Andrew Mitchell, P.E.
PrincipalMitchell Gulledge Engineering, Inc.
LEEDuser Expert
126 thumbs up
June 10, 2014 - 8:29 am
Jason, I saw your question and would like to know if you are trying to certify under LEED v4 or LEED v3. Under v3, you only need to meet the ASHRAE 62.1 2007 standard. In that case, the kitchen exhaust is allowed to be deleted in the case of natural ventilation according to 62.1-2007.
LEED v4 requires you to use ASHRAE 62.1 - 2010. The big difference here (assuming you are not low rise residential) is that natural ventilation is only allowed if there is no heating or cooling equipment or if the ventilation openings are permanently open (they can also be controlled to open whenever occupants are present).
Basically, ASHRAE 62.1 -2010 kills almost all hopes of using natural ventilation in occupied buildings, especially in hot climates. Also, if you are using LEEDv4, then you the v4 forum would be a good place to go for more information during your certification process. I hope this helps.
Jason Biondi
Managing DirectorEnergy Cost Solutions Group
17 thumbs up
June 10, 2014 - 1:03 pm
Thanks Andrew. I was hoping to use V4, however the owner is dead set against ducting O/A into air handler closets... They could be convinced to provide kitchen exhaust to the exterior instead of re circulating hoods and CO2 sensors/alarms but the O/A ducted to the unit seems to be a non starter for this client (based on humidity / mold concerns) . The project is in Miami, mid rise condos and has a 20' wide floor plate with 9'10 ceiling heights and operable openings in every regularly occupied area. In your opinion, Is there a path forward for a project like this?
Thank you for your input.
Jason
Andrew Mitchell, P.E.
PrincipalMitchell Gulledge Engineering, Inc.
LEEDuser Expert
126 thumbs up
June 10, 2014 - 1:27 pm
If you can comply with ASHRAE 62.1-2007 naturaql ventilation then certification under LEEDv3 is certainly possible. LEEDv4 seems impossible without design changes.
On another note, ducted OA from an OA unit (conditioned) would help prevent any mold/mildew problems. I work in Florida and we do a lot of work for UM. We always recommend pressurizing buildings with conditioned OA in order to minimize mold problems.