[Bldg-sim] Infiltration

Macdonald, Iain Iain.Macdonald at nrc-cnrc.gc.ca
Fri Jul 2 07:40:03 PDT 2010


There is active research in this area: ASHRAE RP 1478 Measuring Air-tightness of Mid- and High-Rise Non-residential Buildings. This project is focussing on buildings constructed after 2000.

When complete this will go some way to providing data to some of the unknowns...

Iain

Dr. Iain Macdonald, Ph.D.
Research Officer / Agent de recherches
Indoor Environment Research program / Programme de recherche sur l'environnement intérieur
Institute for Research in Construction / Institut de recherche en construction
National Research Council Canada / Conseil national de recherches Canada
1200 Montréal Road / 1200 chemin Montréal
Ottawa Ontario K1A 0R6
Phone/Tél: (613) 993-9676
Fax: (613) 954-3733
Email: iain.macdonald at nrc-cnrc.gc.ca<mailto:iain.macdonald at nrc-cnrc.gc.ca>
From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of James V Dirkes II, PE
Sent: July 2, 2010 9:48 AM
To: 'Chris Balbach'; bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Infiltration

Amen to that!

Stated another way, almost anyone who thinks they know (with any precision) the infiltration rate of any building is misinformed.

Thanks, Chris, for the references.  I was unfamiliar with them, probably due to giving up hope for any accurate way to estimate infiltration long ago.

That said, more effort is being spent on understanding and reducing infiltration in recent years and, while the estimation of infiltration may not improve, the construction practices which allow infiltration may very well improve as a result!

The Building Performance Team
James V. Dirkes II, P.E., LEED AP
1631 Acacia Drive NW
Grand Rapids, MI 49504
616 450 8653

From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Chris Balbach
Sent: Thursday, July 01, 2010 5:57 PM
To: 'Nick Caton'; 'Vinay Devanathan'; bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Infiltration

Vinay et. al:

Understanding and Estimating Large Building Infiltration.... One of those 'Defense of the Dark Arts' courses at Hogwarts!

Reminds me of a quote from Donald Rumsfield: "... because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns, that is to say we know there are some things we do not know. But there are also unknown unknowns - the ones we don't know we don't know"

Chew on that one for awhile...

If there was such a course, I'd recommend the attached pdf be in the list of required reading.. If nothing else it's a gold mine refererence for explaining to your client why 'measuring' infiltration rates in his/her building, while theoetically possible, it most likely would require an ENORMOUS amount of cash and airflow to generate a meaningful "reference pressure". This document is "solid" on the fundamentals.

So, if you want to do it 'right' - this pdf will help you correctly specify a infiltration measurement test procedure to be performed by a qualified 'Testing Agency. I'd bring several bags of cash with me.

The fallback here that many of us may find useful are the 'standards' tables on pages 5, 6, and 7. If you don't measure, you will have to estimate, and atleast these 'standards' will give you a sense of how 'non-standard' your final estimate is.. We have to work with what we have..

ASHRAE's RP-935: "Protocol for Field Testing of Tall Buildings to Determine Envelope Air Leakage Rate" - (Available free to ASHRAE members through the ASHRAE bookstore) is another good reference to get familiar with possible methods for better understanding the "known unknowns".... As for the "unknown unknowns" - thank god for ASHRAE research.


All the Best,

_Chris

Chris Balbach, PE, CEM BEMP, CMVP
Vice President of Research and Development
Performance Systems Development of NY, LLC
124 Brindley Street, Suite 4, Ithaca NY 14850
http://www.psdconsulting.com
ph: (607)-327-1647




________________________________
From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Nick Caton
Sent: Thursday, July 01, 2010 5:14 PM
To: Vinay Devanathan; bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Infiltration
That's typical in my experience.

Infiltration is figured primarily based on temperature and pressure differential (wind speed vs.interior pressurization) across an exterior surface, among other things.  Lacking any exterior surfaces, I would presume any "interior cross-zonal infiltration" is generally negligible, unless you might be dealing with a large positively pressurized unconditioned space...?

~Nick

[cid:image001.jpg at 01CB19D1.1C4D5340]

NICK CATON, E.I.T.
PROJECT ENGINEER
25501 west valley parkway
olathe ks 66061
direct 913 344.0036
fax 913 345.0617
Check out our new web-site @ www.smithboucher.com

From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Vinay Devanathan
Sent: Thursday, July 01, 2010 2:57 PM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] Infiltration

Hello,

While performing energy modeling, I am guessing it is enough if we account infiltration just for the zones in contact with the exterior environment? Am I right?
Or do we have to include interior zones in infiltration calc?

Thank you.

Regards,
Vinay
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20100702/f128f0e6/attachment-0002.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.jpg
Type: image/jpeg
Size: 1459 bytes
Desc: image001.jpg
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20100702/f128f0e6/attachment-0002.jpg>


More information about the Bldg-sim mailing list