[Bldg-sim] Infiltration Schedule

[Andy hoover]

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. 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 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 Of James 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

 

 

 


  _____  



CONFIDENTIALITY NOTICE:
The information contained in this transmission, as well as any accompanying
documents, constitutes confidential and/or legally privileged information
which is the property of Hallam-ICS. The information is intended solely for
the individual entity named on this transmittal sheet. If you are not the
designated recipient, you are hereby notified that any disclosure, copying,
distribution or taking any action in reliance on this information is
strictly prohibited. If you received this in error, please contact the
sender and delete the material from any computer. Opinions, conclusions and
the information in this message that do not relate to the official business
of my firm shall be understood as neither given nor endorsed by it.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20090209/67efc297/attachment-0001.htm>