[Bldg-sim] Warehouse ventilations to comply with ASHRAE 62.1

Sasa Pantic usrobotics011 at yahoo.com
Wed Jan 26 15:34:23 PST 2011


Hi Jeremy,

In the Gulf region, sand trap louvres are being used at intake side. The sand trap louvre is designed to separate large particles at low air
velocities,minimizing excessive dust loading of conventional
filters.Think of it as a pre-filter for AHU.

Thanks,Sasa


--- On Wed, 1/26/11, Jeremy Poling <Jeremy.Poling at transwestern.net> wrote:

From: Jeremy Poling <Jeremy.Poling at transwestern.net>
Subject: Re: [Bldg-sim] Warehouse ventilations to comply with ASHRAE 62.1
To: "James V Dirkes II, PE" <jvd2pe at tds.net>, "Ashraf Khan" <ashraf at mecsd.com>, bldg-sim at lists.onebuilding.org
Date: Wednesday, January 26, 2011, 7:54 PM

The requirements of ASHRAE 62.1-2004 and 2007 are setup in both a per-person rate to account for respiration-induced IAQ contaminants as well as per-area rate to account for room contents (furniture, materials, etc) induced IAQ contaminants.  The warehouse only has to cover the per-area rate since it is assumed to be non-regularly occupied or have such a low occupant density that it does not impact the overall need for outdoor air.  I’m not certain what the reviewer’s specific comments were, but my guess is they did not see what they were expecting to see for ventilation.  They will not generally comment if the ventilation rate exceeds ASHRAE requirements by a large amount, however.  There may be other reasons to have a high ACH for warehouses: the materials stored, etc.  5-8 ACH is excessively high for cooling needs also and you’d probably be better off air conditioning at that point (haven’t analyzed it specifically, but fan power
 consumption is related to volume in a cubic function, meaning each 10% increase in supply volume requires 33% more power.  Warehouses typically have either a positive pressure design or a negative pressure design – yours using exhaust fans is a negative pressure design.  For Dubai, a positive pressure design using supply fans with exhaust louvers (instead of the opposite) would likely make more sense: less energy to keep the warm air out than to cool it down once it gets in.  Since the project is in Dubai, don’t forget the mandatory Chapter 4 rules in ASHRAE 62.1 on outdoor air cleaning.  If the outdoor air does not pass the U.S. EPA air quality standards, then outdoor air quality must be addressed on any outdoor air used for ventilation purposes.  Particulate will likely be a significant problem.  This does tie in to other LEED credits, particularly EQ Credit 5 (LEED-NC and LEED-CS projects) which requires MERV 13 filters on all outdoor air
 intakes.  You may want to take a step back from the review comments and re-evaluate design intent for the warehouse.  Asking questions like “what will be stored in the warehouse?” and “how often will it be accessed for inbound/outbound shipping and putaway?” will help you figure out what the space needs for ventilation and temperature control.  Then, you can factor in the ASHRAE requirements and bump up the areas where your design intent does not reach the levels necessary.  Good luck on the review!  Jeremy R. Poling, PE, LEED AP+BDC

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: Wednesday, January 26, 2011 10:13 AM
To: 'Ashraf Khan'; bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Warehouse ventilations to comply with ASHRAE 62.1  Dear Ashraf,  Think about it.  If you exhaust X cfm, where does the infiltration come from?  Outdoors!  So you are already introducing hot humid Dubai air into the building.  A (supply)  ventilation system does the same thing as an exhaust-with-infiltration system; it pushes instead of pulls.  As long as the fans actually move the same amount of air, the end result is similar.  (The actual mixing within the space is generally better, though, for a supply system.)     ASHRAE 62 is not confident that the infiltration actually occurs (the building can be constructed very tightly), so they generally want you to have a supply system .  As I think about it, I don’t think they require an exhaust fan, but id the air is introduced, there must be adequate leaks, louvers or exhaust capacity to let it out.    0.06 cfm / sq.ft. is not much.  For a 30ft tall warehouse. 0.5
 cfm/sq.ft. results in 1 AC/hr., so 0.06 cfm/sq.ft.  is around .12 AC/hr (if the building is 30 feet tall).  This amount of air certainly won’t affect your indoor environment noticeably if your exhaust system is 5-8 air changes!   It’s possible that LEED will buy an explanation which discusses why you can be confident that the exhaust fans are providing good ventilation because:·         They are properly spaced around the floor area·         Operate continuously whenever people are present·         Move the correct amount of air because there are louvers or other means to make sure the air can get into the building  Good luck!  It sounds as though you really have good ventilation, but need to make LEED confident about how you are doing it.  The Building Performance Team
James V. Dirkes II, P.E., LEED AP
1631 Acacia Drive NW
Grand Rapids, MI 49504
616 450 8653  From: Ashraf Khan [mailto:ashraf at mecsd.com] 
Sent: Wednesday, January 26, 2011 9:25 AM
To: 'James V Dirkes II, PE'; bldg-sim at lists.onebuilding.org
Subject: RE: [Bldg-sim] Warehouse ventilations to comply with ASHRAE 62.1  James,  If we introduce 0.06 cfm.sqft, of outdoor air, if it complies with ASHRAE requirements, then we can do that.  Normally all warehouses here will be having ventilators to exhaust air which is assumed that air intake by infiltration.  Also project is located in DUBAI, UAE. Climate here is very hot and humid; if I introduce outdoor air it will affect the storage materials in the warehouse.   Did you know where can I find the exhaust rates, such as Toilets, Generator Room, pump room in ASHRAE?  Thanks & Regards,Ashraf  From: James V Dirkes II, PE [mailto:jvd2pe at tds.net] 
Sent: Wednesday, January 26, 2011 5:26 PM
To: 'Ashraf Khan'; bldg-sim at lists.onebuilding.org
Subject: RE: [Bldg-sim] Warehouse ventilations to comply with ASHRAE 62.1  Ashraf,  It seems that all you need to do is demonstrate that your ventilation system complies with Table 6-1.  Are you introducing at least .06 cfm/sq.ft of outdoor air with the mechanical ventilation system?  If so, just document it!  If not, you’re in trouble and will need to provide a ventilation system.        The Building Performance Team
James V. Dirkes II, P.E., LEED AP
1631 Acacia Drive NW
Grand Rapids, MI 49504
616 450 8653  From: Ashraf Khan [mailto:ashraf at mecsd.com] 
Sent: Wednesday, January 26, 2011 8:15 AM
To: 'James V Dirkes II, PE'; bldg-sim at lists.onebuilding.org
Subject: RE: [Bldg-sim] Warehouse ventilations to comply with ASHRAE 62.1  Hello James,  I accept that ASHRAE 62.1 is concerned with people, the same we explained to LEED Reviewer team, this is the comment we received,   However, since the project uses ventilator fans it is considered a mechanically ventilated space. Additionally, the LEED-NC v2.2 IEQp1 CIR ruling dated 10/8/2008 states that unless the mechanically ventilated warehouse has no human occupancy except for maintenance and repairs it must meet the requirements of ASHRAE Standard 62.1-2004. The narrative states that the warehouse will be occupied for the loading and unloading of goods; therefore, the warehouse is regularly occupied. Provide calculations for the warehouse space demonstrating that the space complies with the minimum requirements of ASHRAE Standard 62.1-2004.  I am not having any idea how to convince the team.  Thanks & Regards,AshrafFrom: James V Dirkes II, PE
 [mailto:jvd2pe at tds.net] 
Sent: Wednesday, January 26, 2011 3:46 PM
To: 'Ashraf Khan'; bldg-sim at lists.onebuilding.org
Subject: RE: [Bldg-sim] Warehouse ventilations to comply with ASHRAE 62.1  Ashraf,  ASHRAE 62.1 is concerned with people, who need ventilation (supply / intake).  For typical buildings, you may not need separate exhaust fans, because that amount can probably exfiltrate through cracks.  Supply and exhaust fans can be used in tandem if the building is fairly tight (no leaks).  Your MEP team’s  5-8 air changes per hour is for cooling, not ventilation.  Any building with which has that much infiltration is closer to a tent than a building! (It’s not closed up.)  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 Ashraf Khan
Sent: Tuesday, January 25, 2011 11:55 PM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] Warehouse ventilations to comply with ASHRAE 62.1  We received a LEED review comment regarding Warehouse ventilation to comply with ASHRAE 62.1-2004.  Generally depending on the warehouse storage, MEP team recommends 5-8 Air Changes per Hour by thumb rule for exhaust and air intake is assumed by infiltration by windows, open doors etc.. But this number I haven’t find in ASHRAE, please give me reference.  ASHRAE 62.1-2004, Table 6-1 for warehouse category says to have 0.06 cfm/ft2, is this number defines to intake or Exhaust? If it is exhaust, it is too small as volume of warehouse will be high.  Please share your ideas to comply with the requirements.  Thanks & Regards,Ashraf
-----Inline Attachment Follows-----

_______________________________________________
Bldg-sim mailing list
http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
To unsubscribe from this mailing list send  a blank message to BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG



      
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20110126/833908f6/attachment-0002.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/jpeg
Size: 43145 bytes
Desc: image003.jpg
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20110126/833908f6/attachment-0002.jpeg>


More information about the Bldg-sim mailing list