[Bldg-sim] Infiltration Schedule

Jesse Thompson jesse at kaplanthompson.com
Tue Feb 10 07:20:31 PST 2009


Best thing I have read lately on real world commercial scale air  
infiltration is in the Journal of Building Enclosure Design, Winter  
2007 issue:  http://www.nibs.org/jbed.html

PDF here:  http://www.nibs.org/JBED/JBED_Winter07.pdf


Jesse Thompson, AIA, LEED AP
Kaplan Thompson Architects
424 Fore St
Portland, ME  04101

p: 	207 842-2888
f:	207 842-2828

jesse at kaplanthompson.com
http://www.kaplanthompson.com



On Feb 9, 2009, at 11:32 AM, Andy hoover wrote:

> Hey folks:
>
> We have done similar things to control outside air and create  
> positive pressure then look at the losses in a variety of ways and  
> have seen reports of work done by various labs and even reports on  
> whole buildings with the giant tractor trailer blower unit.  They  
> always see much much higher than predicted/designed infiltration and  
> higher energy cost/comfort issues but not always significantly (5%  
> is significant to me but not to all) higher cost in heavy cooling  
> areas due to what seems to be both the infiltration that occurs when  
> the conditioned air is cooler/less humid on the interior and the  
> comparatively low cost to cool.
>
> We have very limited experience in industrial but in office,  
> commercial, retail, and similar have seen from James numbers (his  
> range is mostly the low end we have seen) to 5 times them and even  
> more.   The numbers tend to go completely crazy when we have tried  
> to look at real world effects and apply parameters such as actual in  
> use conditions for office, commercial or retail buildings.  We have  
> never seen an existing building that was at the ‘design  
> parameters’.  I am not saying that as a negative toward anyone who  
> did or does design nor about the assumptions in the models but am  
> saying that it needs to be looked at as we need to end up saving  
> most of our energy, carbon, cost, whatever all you care about  
> through work on existing structures.  We can not build our way to  
> enough savings of any type particularly in a 10 to 30 year horizon.
>
> I would not presume no infiltration at plenums (2 years after a  
> building is up seal up an area, pressurize it and see what you get)  
> and would assume significant infiltration at penthouses, elevator  
> rooms, and so on.
>
> Eric, my thought would be that if you are going to apply a number  
> across the board, so to speak, you may want to go to .20 bare  
> minimum and I would suggest .25.  My bet is James does a lot of .4  
> to .5 in design work with very tight structures.
>
> We have not yet done anything specifically following the letter of  
> the newer large building standards/suggestions for testing from ASTM/ 
> ASHRAE et al.
>
> Thanks,
>
> Andy
>
> Andy Hoover
> Principal
> The BEST Consultant, Inc.
> Office: 678-200-7648
> Fax:678-827-0574
> Cell: 678-793-1159
>
> www.thebestconsultant.com
>
>
> This message may contain confidential and/or privileged information.  
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>
> From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org 
> ] On Behalf Of James V. Dirkes II P.E.
> Sent: Monday, February 09, 2009 9:12 AM
> To: 'Doug Maddox'; 'Eric Studer'; bldg-sim at lists.onebuilding.org
> Subject: Re: [Bldg-sim] Infiltration Schedule
>
> You don't really do blower door testing on 100,000 - 1,000,000 sq.ft  
> factory buildings, however we did something that was roughly  
> equivalent.  My company's air handler product normally used a  
> control loop that monitored differential pressure between the  
> building and the outdoors, and then controlled the outdoor air  
> amount to maintain a slight (0.01") positive pressure.  Since the  
> controls were very often digital and we could obtain data from the  
> AHU performance, we knew what the outdoor air control was doing over  
> the course of a day, or weeks, or months.
>
> From that information, we created some "rules of thumb" that were  
> applied to new projects.
>
> The Building Performance Team
> James V. Dirkes II, P.E., LEED AP
> 1631 Acacia Drive NW
> Grand Rapids, MI 49504
> 616 450 8653
>
>
>
> From: Doug Maddox [mailto:DougM at TWGI.com]
> Sent: Monday, February 09, 2009 8:59 AM
> To: James V. Dirkes II P.E.; Eric Studer; bldg-sim at lists.onebuilding.org
> Subject: RE: [Bldg-sim] Infiltration Schedule
> Is the 0.2 to 0.5 ACH based on blower door testing?  Did you apply  
> some sort of conversion to get from the blower door pressure  
> differential to a typical real world pressure?
>
> Doug Maddox
>
> The Weidt Group
>
> From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org 
> ] On Behalf OfJames V. Dirkes II P.E.
> Sent: Monday, February 09, 2009 7:30 AM
> To: 'Eric Studer'; bldg-sim at lists.onebuilding.org
> Subject: Re: [Bldg-sim] Infiltration Schedule
>
> Dear Andy and Eric,
>
> My past experience with industrial buildings (manufacturing,  
> assembly, warehouses, etc) indicates that a good building has an  
> AVERAGE winter AC/hr of ~0.2.  Poor buildings are on the order of  
> 0.5 (or more!)
>
> This doesn't address residences (which often have much higher  
> infiltration rates) offices or high rises, but it may be helpful.   
> Most of the literature I'm familiar with indicates that infiltration  
> is normally a lot higher than is generally assumed.  My experience  
> confirms that.
>
> 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 Eric Studer
> Sent: Monday, February 09, 2009 6:42 AM
> To: bldg-sim at lists.onebuilding.org
> Subject: Re: [Bldg-sim] Infiltration Schedule
> I tend to model an air exchange rate of 0.15 ACH in perimeter spaces  
> during unoccupied hours (e.g. outside air fans are off with dampers  
> closed) for new buildings (even if they have air barriers).   
> Vestibules, conditioned loading docks, etc usually get higher air  
> change rates.  Zones with no exterior exposure should not be modeled  
> as having any infiltration since there is not a way for air at  
> outside conditions to make it to these zones.  I assume no  
> infiltration into plenum zones.
>
> I am curious to know whether or not this seems reasonable based on  
> real world experience.  Andy, any thoughts?
>
> Thanks,
>
> Eric
>
> Ph:   (781) 431-1100 ext 12
> Fax:  (781) 431-1109
>
> From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org 
> ] On Behalf Of Andy hoover
> Sent: Friday, February 06, 2009 5:07 PM
> To: 'Talbert, Joshua'; bldg-sim at lists.onebuilding.org
> Subject: Re: [Bldg-sim] Infiltration Schedule
>
> Hi all:
>
> We do building envelope consulting and are very curious as to what  
> folks do and what rates they use whatever approach.  When looking at  
> buildings we find that most  infiltrate much more in the real world  
> than designers estimate and that the fluctuations are far greater  
> than predicted.  We would also love it if anyone has any experiences  
> which can be shared.
>
> Thanks,
>
> Andy
>
> Andy Hoover
> Principal
> The BEST Consultant, Inc.
> Office: 678-200-7648
> Fax:678-827-0574
> Cell: 678-793-1159
>
> www.thebestconsultant.com
>
>
> This message may contain confidential and/or privileged information.  
> If you are not the addressee or authorized to receive this  
> information for the addressee, you must not use, copy, disclose, or  
> take any action based on this message or information herein. If you  
> have received this message in error, please advise the sender  
> immediately by reply e-mail and delete this message. Thank you for  
> your cooperation.
>
> From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org 
> ] On Behalf Of Talbert, Joshua
> Sent: Friday, February 06, 2009 10:30 AM
> To: bldg-sim at lists.onebuilding.org
> Subject: [Bldg-sim] Infiltration Schedule
>
> Howdy Bldg Sim peers!
>
> While working on LEED Equest simulations I find that in an effort to  
> simplify I end up deleting the P-Inf and C-Inf Infiltration  
> Schedules all of the time and end just use "undefined" to simulate a  
> constant infiltration rate.  I was curious to know if anyone uses  
> the actual Infiltrations schedules, to emulate winds and or building  
> pressurization, and if so do you typically achieve more energy  
> savings, and do you find it worth the extra effort?
>
> Thanks all and be well.
>
> Josh
> Joshua W. Talbert P.E., LEED-AP
> Mechanical Engineer
> Hallam///ICS
> 38 Eastwood Dr. Suite 200
> S. Burlington, VT 05403
> P: (802) 658-4891
> F: (802) 658-1457
>
>
>
>
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