<html>
<body>
Ouch!<br>
In the Model energy code in Canada only up to 20% more than ASHRAE 62 is
allowed in the base case. Imagine a building with 100% more OA and
a ERV of 70% on the proposed case it can easily reach 10 EAcr1 point
especially in cold climate.<br><br>
Martin<br><br>
<br>
At 21:41 15/11/2011, Reba Schaber wrote:<br>
<blockquote type=cite class=cite cite="">Content-Language: en-US<br>
Content-Type: multipart/alternative;<br>
<x-tab> </x-tab>
boundary="_000_FAA9B7F58E5E4A46BDDF900F4CCAC3FE03ABA763DD3DPHSERVERphm_"<br>
<br>
RE: <i>“. . . can’t find) anything in 621.1 which says that
unoccupied ventilation should be zero.”<br>
<br>
</i>I think this requirement comes from the mandatory provisions of
90.1.<br>
<br>
<b>6.4.3.4.3 Shutoff Damper Controls. </b>Both <i>outdoor<br>
air </i>supply and exhaust systems shall be equipped with motorized<br>
dampers that will automatically shut when the systems or<br>
spaces served are not in use. Ventilation <i>outdoor air </i>dampers<br>
shall be capable of automatically shutting off during preoccupancy<br>
building warm-up, cool down, and <i>setback, </i>except<br>
when <i>ventilation </i>reduces energy costs (e.g., night purge) or<br>
when ventilation must be supplied to meet code requirements.<br>
<br>
Thoughts??<br>
<br>
Reba<br>
<br>
<b>From:</b> bldg-sim-bounces@lists.onebuilding.org
[<a href="mailto:bldg-sim-bounces@lists.onebuilding.org" eudora="autourl">
mailto:bldg-sim-bounces@lists.onebuilding.org</a>] <b>On Behalf Of
</b>Jim Dirkes<br>
<b>Sent:</b> Monday, October 17, 2011 9:32 AM<br>
<b>To:</b> equest-users@lists.onebuilding.org;
'bldg-sim@lists.onebuilding.org'<br>
<b>Subject:</b> Re: [Bldg-sim] usgbc response to outdoor air
question<br>
<br>
Dear Patrick,<br>
<br>
Thank you for sharing this GBCI response! It is very informative
and, while I won’t admit that I’ve been modeling anything incorrectly, I
<u>am</u> going to change a couple of things J.<br>
In particular, I have heard on several occasions that the Increased
Ventilation credit was a clear case of “IEQ vs. energy”; you make a
decision to trade one against the other. After reading the GBCI
response below and then double-checking with ASHRAE 90.1, I find that
they are consistent with each other and effectively allow no penalty for
the increased energy caused by increased ventilation. Very curious,
considering there is no science which demonstrates a health benefit for
outdoor airflows greater than that required by ASHRAE 62.1!<br>
The other item is that I failed to notice (and still can’t find) anything
in 621.1 which says that unoccupied ventilation should be zero. I
guess that is OK, but is also curious, since a portion of the ventilation
calcs in 62.1 include consideration for off-gassing materials (which are
always present.)<br>
All in all, I’m smarter than I was as a result of your post, so it’s a
good day! Thanks again.<br>
<br>
<div align="center"><b>The Building Performance Team<br>
James V. Dirkes II, P.E., BEMP , LEED AP<br>
</b>1631 Acacia Drive NW<br>
Grand Rapids, MI 49504<br>
616 450 8653<br>
</div>
<br>
<b>From:</b>
<a href="mailto:bldg-sim-bounces@lists.onebuilding.org">
bldg-sim-bounces@lists.onebuilding.org</a>
[<a href="mailto:bldg-sim-bounces@lists.onebuilding.org" eudora="autourl">
mailto:bldg-sim-bounces@lists.onebuilding.org</a>] <b>On Behalf Of
</b>Patrick J. O'Leary, Jr.<br>
<b>Sent:</b> Monday, October 17, 2011 11:46 AM<br>
<b>To:</b>
<a href="mailto:equest-users@lists.onebuilding.org">
equest-users@lists.onebuilding.org</a>;
<a href="mailto:bldg-sim@lists.onebuilding.org">
bldg-sim@lists.onebuilding.org</a><br>
<b>Subject:</b> [Bldg-sim] usgbc response to outdoor air question<br>
<br>
back in september there was a thread about what the outdoor air rate in a
baseline simulation should be compared to a proposed simulation,
specifically when one is adding 30% more outdoor air to meet the ieqc2
requirement and earn 1 leed point. there were differences of
opinions about the flow rates between baseline and proposed being either
the same (as required in 90.1 app g) or the baseline being the calculated
per 62.1 and the proposed being as designed.<br><br>
so i submitted a support request to the usgbc and the reply i received is
below, but in short the response is that unless you're using dcv
optionally the outdoor air rates in the baseline and proposed energy
simulations for eac1 should be the same. the response below gives
the standard responses to differing outdoor air rate scenarios.<br><br>
regards,<br>
patrick<br><br>
[Fwd: Case 00531150: General LEED Questions<br><br>
-------- Original Message --------<br>
<div align="right"><b>Subject: <br>
</b></div>
<br>
Case 00531150: General LEED Questions [ ref:00D49UeD.5004GN692:ref ]<br>
<div align="right"><b>Date: <br>
</b></div>
<br>
Mon, 17 Oct 2011 06:54:51 +0000 (GMT)<br>
<div align="right"><b>From: <br>
</b></div>
<br>
"No reply GBCI"
<a href="mailto:no-reply@gbci.org"><no-reply@gbci.org></a>
<a href="mailto:no-reply@gbci.org"><no-reply@gbci.org></a><br>
<div align="right"><b>To: <br>
</b></div>
<br>
patrick@<br><br>
<br>
Dear Patrick,<br><br>
Thank you for contacting the Green Building Certification Institute.
<br><br>
You ask very good questions related to the relationship between ASHRAE
Standards 62.1 and 90.1, and how these standards are applied across
multiple LEED Rating System prerequisites and credits.<br><br>
The simple answer to your question is that, for systems without demand
controlled ventilation, the outdoor air included in EA Credit 1 energy
simulations must be the same in the Baseline and Proposed cases. If the
project is attempting IEQ Credit 2 Increased Ventilation, then the values
calculated in IEQc2 must be used in the EAc1 Basline and Proposed case
energy models. Note that IEQc2 does not limit the project to providing
only 30% more outdoor air than AHRAE 62.1 Ventilation Rate Procedure
minimums, so higher amounts are acceptable, as long as they are modeled
identically in both the Baseline and Proposed case energy
models.<br><br>
The following generic LEED Review Comment applies to ventilation systems
that do not have demand controlled ventilation:<br>
<br>
It is unclear whether the minimum outside air rates (in CFM) were modeled
identically in the Baseline and Proposed case for all zones not having
Demand Control Ventilation in the Proposed case. Please confirm that
minimum outside airflow (in units of cfm) was modeled identically in the
Baseline and Proposed cases using the proposed case rates. Additionally,
please verify that all systems in both the baseline and proposed case are
modeled with zero outside air flow when fans are cycled on to meet
unoccupied setback temperatures unless health or safety regulations
mandate an alternate minimum flow during unoccupied periods (in which
case, the unoccupied outside air rates should be modeled identically in
the Baseline and Proposed case).<br><br>
The situation becomes a bit more complicated in you have systems that
have demand controlled ventilation (often implemented as Carbon Dioxide
control of outdoor air or as programmed control of outdoor air based on
occupancy sensors.) In this case the Baseline case energy model must
include the minimum outdoor air as determined by the ASHRAE 62.1
Ventilation Rate Procedure calculations for all systems having demand
controlled ventilation. <br><br>
The following generic LEED Review Comment applies to ventilation systems
that do have demand controlled ventilation:<br><br>
Demand control ventilation was modeled for credit in the proposed case.
Appendix G allows schedule changes for demand control ventilation as
approved by the rating authority (Table G3.1#4(Baseline)). As the LEED
Certification rating authority, GBCI requires that the outside air
ventilation rates for the Baseline case be modeled using minimum ASHRAE
62.1-2004 (or 2007 for LEED-NC 2009 projects) rates wherever credit is
taken for demand control ventilation in the Proposed case. The proposed
case minimum rates at design conditions should be modeled as designed.
Please verify that the Baseline Case model reflects ASHRAE 62.1-2004 (or
2007) minimum rates for any spaces where credit is taken for demand
control ventilation, or revise the model accordingly. For all other
spaces, please confirm that minimum outside airflow (in units of cfm) was
modeled identically in the Baseline and Proposed cases. Additionally,
please verify that all systems in both the baseline and proposed cases
are modeled with zero outside air flow when fans are cycled on to meet
unoccupied setback temperatures unless health or safety regulations
mandate an alternate minimum flow during unoccupied periods (in which
case, the unoccupied outside air rates should be modeled identically in
the Baseline and Proposed case).<br><br>
Finally, even though you don't address energy recovery in your question,
whether or not you have energy recovery in your ventilation systems may
affect how much better (or worse) your Proposed case energy models
perform in relation to your Baseline case energy models. <br><br>
The following generic LEED Review Comment addresses energy recovery in
EAc1 energy models as it relates to ventilation systems.<br><br>
Energy recovery is modeled for credit in the Proposed case. Please
provide further information regarding the energy recovery efficiency,
verify that outside air is modeled with zero flow in both the Baseline
and Proposed cases during unoccupied periods when fans are cycled on to
meet unoccupied setback temperatures unless health or safety regulations
mandate an alternate minimum flow during unoccupied periods (in which
case, the unoccupied outside air rates should be modeled identically in
the Baseline and Proposed Case), and indicate the bypass mechanism used
to bypass the energy recovery during mild conditions. <br><br>
I hope that helps, but if you have any further questions or concerns,
please feel free to use the contact form at
<a href="http://www.gbci.org/contactus">http://www.gbci.org/contactus</a>
and select "Follow up to GBCI Response," inputting your case
number from this email's subject line.<br><br>
Best Regards,<br><br>
Dan Katzenberger, P.E., CEM, BEMP, LEED-AP BD+C<br><br>
Green Building Certification Institute <br>
2101 L Street NW, Suite 500 <br>
Washington, DC 20037 <br>
800-795-1746 (phone)<br>
202 828-5110 (fax) <br>
<a href="http://www.gbci.org/contactus">www.gbci.org/contactus</a><br><br>
The text above represents a staff opinion of a particular issue, and does
NOT set any precedent to be upheld during a LEED Certification Review.
For official rulings in advance of a LEED Certification Review, customers
should utilize the Formal Inquiries process available in LEED Online that
results in a Project Credit Interpretation Ruling (Project CIR) and
possibly a LEED Interpretation (formerly CIRs or Public Rulings).
Applications for LEED Certification will be thoroughly reviewed based on
USGBC Member balloted and approved LEED Rating Systems, with addenda, and
USGBC approved LEED Interpretations, or Project CIRs administered by
GBCI, as applicable. Please note that certain inquiries submitted to
USGBC are forwarded to GBCI for reply as appropriate.<br><br>
<br>
_______________________________<br>
CUSTOMER EMAIL ADDRESS: <br>
patirck@<br><br>
CUSTOMER INQUIRY:<br>
I am trying to verify what the minimum outdoor airflow rate required for
EAc1 is and am not sure if this requires a CIR. <br><br>
If the Proposed outdoor air ventilation is a minimum of 30% higher than
the minimum required by ASHRAE 62 in order to achieve 1 LEED point for
credit IEQC2 is the Baseline outdoor air rate also 30% higher than the
minimum required by ASHRAE 62? or would the Baseline outdoor air
ventilation rate be the minimum outdoor air rate per ASHRAE 62
calculations. <br><br>
In other words, if ASHRAE 62 requires a minimum of 1,000 CFM of outdoor
air, and 1,300 CFM is provided to attain 1 LEED point via IEQC1, is the
Baseline outdoor air flow rate 1,000 CFM or 1,300 CFM in the energy
simulation? <br><br>
90.1-2007/2004 both say the minimu m outdoor airflow
rates shall be the same for both the proposed and baseline building
designs, as does the user manual. <br><br>
But this logic seems to reward the Proposed simulation by conditioning
the additional outdoor air supplied (300 cfm in the example above) to
achieve IEQC1 in the Baseline system as well as the proposed. <br><br>
The logic of using the minimum required in the Baseline case is reflected
in EAC1 in the equipment efficiency requirements. Baseline efficiencies
are the minimum required, e.g. SEER 13 for packaged units. <br><br>
It is the intent of the requirement that I am not sure is clear.
Increasing the outdoor air ventilation rate increases the energy used to
condition the outdoor air, so if the intent is to put the onus on
Proposed design to show energy reduction/LEED compliance over the 90.1/62
requirements shouldn't the Baseline outdoor air be the minimum air flow
rate per the ASHRAE 62 calculations? This puts the onus on the design
team to provide a design that compensates for the increase in energy to
meet IEQC2 by providing some method of processing the increase in outdoor
air while still reducing energy consumption.<br>
_______________________________________________<br>
Bldg-sim mailing list<br>
<a href="http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org" eudora="autourl">
http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org</a><br>
To unsubscribe from this mailing list send a blank message to
BLDG-SIM-UNSUBSCRIBE@ONEBUILDING.ORG</blockquote>
<x-sigsep><p></x-sigsep>
<hr>
<br>
Martin Roy, ing. PA LEED®, président<br>
Martin Roy et associés<br>
1805 chemin Oka, <br>
Deux-Montagnes, Qc<br>
J7R 1N3<br><br>
<br>
Tel: 450-623-0340<br>
Cell. 514-594-6352<br><br>
<a href="http://www.mra.qc.ca/" eudora="autourl">www.mra.qc.ca<br><br>
<br><br>
<br><br>
<br>
</a><b>Message de confidentialité <br>
</b>Ce courriel (de même que les fichiers joints) est strictement réservé
à l'usage de la personne ou de l'entité à qui il est adressé et peut
contenir de l'information privilégiée et confidentielle. Toute
divulgation, distribution ou copie de ce courriel est strictement
prohibée et peut être l’objet de poursuites judiciaires. Si vous avez
reçu ce courriel par erreur, veuillez nous en aviser et le
supprimer de votre système informatique sans l'imprimer, le copier ou le
faire suivre a quiconque. <br><br>
<b>Devez-vous vraiment imprimer ce courriel ? Pensons
environnement...<br>
</b></body>
</html>