[Bldg-sim] modelling stratification in houses

Hayes Zirnhelt hzirnhelt at hotmail.com
Wed Nov 16 16:34:44 PST 2011


Hi,

I'm modelling single family dwellings in EnergyPlus, and I am wondering about the accuracy of the typical assumption that the zones are fully mixed .

The results of my modelling are showing that the high ratio of ceiling insulation to wall insulation required by the codes (BC and Canada) seems to higher than practical (i.e. no point having an R50 roof if your walls are only R16). However, this is making me wonder if I should be trying to account for the stratification that occurs in reality (which would increase losses through the roof).

Anyone have any experience with modelling stratification in a scenario like this? Or know of some empirical studies where the stratification has been measured? I'm pretty sure I can set up a temperature gradient in the zone if I know what it should be...

Thanks!

Hayes

Hayes Zirnhelt
M.A.Sc Candidate, RU Building Science
B.A.Sc Integrated Engineering
hayes.zirnhelt at ryerson.ca


On 2011-11-16, at 1:30 PM, bldg-sim-request at lists.onebuilding.org wrote:

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> 
>   1. eQuest - Heating/Cooling Loads (Katherine Louman-Gardiner)
>   2. Re: eQuest - Heating/Cooling Loads (Katherine Louman-Gardiner)
>   3. Re: usgbc response to outdoor air question (Reba Schaber)
>   4. Re: usgbc response to outdoor air question
>      (Martin Roy ing. LEED AP)
>   5. EnergyPlus: Outlet Nodes not matching error (Sachin Sharma)
>   6. Re: usgbc response to outdoor air question
>      (Patrick J. O'Leary, Jr.)
>   7. Re: usgbc response to outdoor air question (Jim Dirkes)
>   8. Re: EnergyPlus: Outlet Nodes not matching error (Linda Lawrie)
>   9. Re: usgbc response to outdoor air question (Jeremy Poling)
>  10. HELP WANTED: Energy Modeler SWA (NY-CT) (Sandor Rosta)
> 
> From: "Katherine Louman-Gardiner" <klgardiner at flowgroup.ca>
> Date: November 15, 2011 2:57:02 PM PST
> To: <bldg-sim at lists.onebuilding.org>
> Subject: [Bldg-sim] eQuest - Heating/Cooling Loads
> 
> 
> Hi all,
> I’m not sure I understand how eQuest calculates the heating/cooling equipment loads.
> I’ve built two models with identical envelopes and internal loads etc, and OA supply.  In model A, we have a boiler and chiller on hot and chilled water loops and a four-pipe fan coil air-side system.  In model B, we’re using an air cooled Heat Pump and two-pipe fan coils.
> In report PS-C for model A, the sum heat load is -29.6 MBTU, whereas for model B, the sum heat load is -130.2 MBTU.  I understand that the fuel use should be very different, but I don’t know why the load is so different between the models.  Shouldn’t the heating energy delivered to the spaces be the same in both cases?  Why does the Heat Pump system have a load that is so much higher than its counterpart?
>  
> Similarly, in report SS-E, January has 110 Heating load hours for Model A, and 385 Heating load hours for Model B.  Again, shouldn’t the loads be the same between the two models? 
>  
> Thanks in advance for the help,
>  
> Katherine
> 
> 
> 
> From: "Katherine Louman-Gardiner" <klgardiner at flowgroup.ca>
> Date: November 15, 2011 4:06:48 PM PST
> To: <bldg-sim at lists.onebuilding.org>
> Subject: Re: [Bldg-sim] eQuest - Heating/Cooling Loads
> 
> 
> Thanks Brian,
> But I’d already examined LS-C, LS-D, SS-C and SS-D.  As one would expect, LS-C and LS-D are the same for both models.  SS-D, however, is not.  I guess what I don’t understand is what eQuest considers a “load” to be.  I consider “load” to be the requirements of the space (including envelope, occupants, and OA), and none of those things have changed between my models.  The only thing that changes is what system is used to meet the load. 
> SS-D only has a monthly breakdown – but doesn’t explain why the loads are different.
>  
> Thanks,
> Katherine
>  
> From: Brian Fountain [mailto:greensimbf at gmail.com] On Behalf Of Brian Fountain
> Sent: November-15-11 3:15 PM
> To: Katherine Louman-Gardiner
> Subject: Re: [Bldg-sim] eQuest - Heating/Cooling Loads
>  
> Look at the SS-D and LS-C reports.  SS-D shows the peak heating & cooling loads with outdoor air, LS-C shows the same without outdoor air ... but will show components so you can determine where the difference is.  
> 
> 
> On 11/15/2011 5:57 PM, Katherine Louman-Gardiner wrote:
> Hi all,
> I’m not sure I understand how eQuest calculates the heating/cooling equipment loads.
> I’ve built two models with identical envelopes and internal loads etc, and OA supply.  In model A, we have a boiler and chiller on hot and chilled water loops and a four-pipe fan coil air-side system.  In model B, we’re using an air cooled Heat Pump and two-pipe fan coils.
> In report PS-C for model A, the sum heat load is -29.6 MBTU, whereas for model B, the sum heat load is -130.2 MBTU.  I understand that the fuel use should be very different, but I don’t know why the load is so different between the models.  Shouldn’t the heating energy delivered to the spaces be the same in both cases?  Why does the Heat Pump system have a load that is so much higher than its counterpart?
>  
> Similarly, in report SS-E, January has 110 Heating load hours for Model A, and 385 Heating load hours for Model B.  Again, shouldn’t the loads be the same between the two models? 
>  
> Thanks in advance for the help,
>  
> Katherine
> 
> 
> 
> _______________________________________________
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> 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
> 
> 
> 
> From: Reba Schaber <Rschaber at PHMECH.com>
> Date: November 15, 2011 6:41:36 PM PST
> To: Jim Dirkes <jim at buildingperformanceteam.com>, "equest-users at lists.onebuilding.org" <equest-users at lists.onebuilding.org>, "'bldg-sim at lists.onebuilding.org'" <Bldg-sim at lists.onebuilding.org>
> Subject: Re: [Bldg-sim] usgbc response to outdoor air question
> 
> 
> RE:  “. . . can’t find) anything in 621.1 which says that unoccupied ventilation should be zero.”
>  
> I think this requirement comes from the mandatory provisions of 90.1.
>  
> 6.4.3.4.3 Shutoff Damper Controls. Both outdoor
> air supply and exhaust systems shall be equipped with motorized
> dampers that will automatically shut when the systems or
> spaces served are not in use. Ventilation outdoor air dampers
> shall be capable of automatically shutting off during preoccupancy
> building warm-up, cool down, and setback, except
> when ventilation reduces energy costs (e.g., night purge) or
> when ventilation must be supplied to meet code requirements.
>  
> Thoughts??
>  
> Reba
>  
> From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Jim Dirkes
> Sent: Monday, October 17, 2011 9:32 AM
> To: equest-users at lists.onebuilding.org; 'bldg-sim at lists.onebuilding.org'
> Subject: Re: [Bldg-sim] usgbc response to outdoor air question
>  
> Dear Patrick,
>  
> 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 am going to change a couple of things J.
> 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!
> 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.)
> All in all, I’m smarter than I was as a result of your post, so it’s a good day!  Thanks again.
>  
> The Building Performance Team
> James V. Dirkes II, P.E., BEMP , 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 Patrick J. O'Leary, Jr.
> Sent: Monday, October 17, 2011 11:46 AM
> To: equest-users at lists.onebuilding.org; bldg-sim at lists.onebuilding.org
> Subject: [Bldg-sim] usgbc response to outdoor air question
>  
> 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.
> 
> 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.
> 
> regards,
> patrick
> [Fwd: Case 00531150: General LEED Questions
> 
> -------- Original Message --------
> 
> Subject:
> Case 00531150: General LEED Questions [ ref:00D49UeD.5004GN692:ref ]
> 
> Date:
> Mon, 17 Oct 2011 06:54:51 +0000 (GMT)
> 
> From:
> "No reply GBCI" <no-reply at gbci.org> <no-reply at gbci.org>
> 
> To:
> patrick@
> 
>  
> 
> Dear Patrick,
> 
> Thank you for contacting the Green Building Certification Institute. 
> 
> 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.
> 
> 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.
> 
> The following generic LEED Review Comment applies to ventilation systems that do not have demand controlled ventilation:
> 
> 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).
> 
> 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. 
> 
> The following generic LEED Review Comment applies to ventilation systems that do have demand controlled ventilation:
> 
> 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).
> 
> 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. 
> 
> The following generic LEED Review Comment addresses energy recovery in EAc1 energy models as it relates to ventilation systems.
> 
> 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. 
> 
> I hope that helps, but if you have any further questions or concerns, please feel free to use the contact form at http://www.gbci.org/contactus and select "Follow up to GBCI Response," inputting your case number from this email's subject line.
> 
> Best Regards,
> 
> Dan Katzenberger, P.E., CEM, BEMP, LEED-AP BD+C
> 
> Green Building Certification Institute 
> 2101 L Street NW, Suite 500 
> Washington, DC 20037 
> 800-795-1746 (phone)
> 202 828-5110 (fax) 
> www.gbci.org/contactus
> 
> 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.
> 
> 
> _______________________________
> CUSTOMER EMAIL ADDRESS: 
> patirck@
> 
> CUSTOMER INQUIRY:
> I am trying to verify what the minimum outdoor airflow rate required for EAc1 is and am not sure if this requires a CIR. 
> 
> 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. 
> 
> 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? 
> 
> 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. 
> 
> 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. 
> 
> 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. 
> 
> 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.
> 
> 
> 
> From: "Martin Roy ing. LEED AP" <martin.roy at mra.qc.ca>
> Date: November 15, 2011 7:15:12 PM PST
> To: Reba Schaber <Rschaber at PHMECH.com>
> Cc: "equest-users at lists.onebuilding.org" <equest-users at lists.onebuilding.org>, "'bldg-sim at lists.onebuilding.org'" <Bldg-sim at lists.onebuilding.org>
> Subject: Re: [Bldg-sim] usgbc response to outdoor air question
> 
> 
> Ouch!
> 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.
> 
> Martin
> 
> 
> At 21:41 15/11/2011, Reba Schaber wrote:
>> Content-Language: en-US
>> Content-Type: multipart/alternative;
>>          boundary="_000_FAA9B7F58E5E4A46BDDF900F4CCAC3FE03ABA763DD3DPHSERVERphm_"
>> 
>> RE:  “. . . can’t find) anything in 621.1 which says that unoccupied ventilation should be zero.”
>>  
>> I think this requirement comes from the mandatory provisions of 90.1.
>>  
>> 6.4.3.4.3 Shutoff Damper Controls. Both outdoor
>> air supply and exhaust systems shall be equipped with motorized
>> dampers that will automatically shut when the systems or
>> spaces served are not in use. Ventilation outdoor air dampers
>> shall be capable of automatically shutting off during preoccupancy
>> building warm-up, cool down, and setback, except
>> when ventilation reduces energy costs (e.g., night purge) or
>> when ventilation must be supplied to meet code requirements.
>>  
>> Thoughts??
>>  
>> Reba
>>  
>> From: bldg-sim-bounces at lists.onebuilding.org [ mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Jim Dirkes
>> Sent: Monday, October 17, 2011 9:32 AM
>> To: equest-users at lists.onebuilding.org; 'bldg-sim at lists.onebuilding.org'
>> Subject: Re: [Bldg-sim] usgbc response to outdoor air question
>>  
>> Dear Patrick,
>>  
>> 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 am going to change a couple of things J.
>> 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!
>> 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.)
>> All in all, I’m smarter than I was as a result of your post, so it’s a good day!  Thanks again.
>>  
>> The Building Performance Team
>> James V. Dirkes II, P.E., BEMP , 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 Patrick J. O'Leary, Jr.
>> Sent: Monday, October 17, 2011 11:46 AM
>> To: equest-users at lists.onebuilding.org; bldg-sim at lists.onebuilding.org
>> Subject: [Bldg-sim] usgbc response to outdoor air question
>>  
>> 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.
>> 
>> 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.
>> 
>> regards,
>> patrick
>> 
>> [Fwd: Case 00531150: General LEED Questions
>> 
>> -------- Original Message --------
>> Subject: 
>> 
>> Case 00531150: General LEED Questions [ ref:00D49UeD.5004GN692:ref ]
>> Date: 
>> 
>> Mon, 17 Oct 2011 06:54:51 +0000 (GMT)
>> From: 
>> 
>> "No reply GBCI" <no-reply at gbci.org> <no-reply at gbci.org>
>> To: 
>> 
>> patrick@
>> 
>>  
>> Dear Patrick,
>> 
>> Thank you for contacting the Green Building Certification Institute. 
>> 
>> 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.
>> 
>> 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.
>> 
>> The following generic LEED Review Comment applies to ventilation systems that do not have demand controlled ventilation:
>> 
>> 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).
>> 
>> 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. 
>> 
>> The following generic LEED Review Comment applies to ventilation systems that do have demand controlled ventilation:
>> 
>> 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).
>> 
>> 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. 
>> 
>> The following generic LEED Review Comment addresses energy recovery in EAc1 energy models as it relates to ventilation systems.
>> 
>> 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. 
>> 
>> I hope that helps, but if you have any further questions or concerns, please feel free to use the contact form at http://www.gbci.org/contactus and select "Follow up to GBCI Response," inputting your case number from this email's subject line.
>> 
>> Best Regards,
>> 
>> Dan Katzenberger, P.E., CEM, BEMP, LEED-AP BD+C
>> 
>> Green Building Certification Institute 
>> 2101 L Street NW, Suite 500 
>> Washington, DC 20037 
>> 800-795-1746 (phone)
>> 202 828-5110 (fax) 
>> www.gbci.org/contactus
>> 
>> 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.
>> 
>> 
>> _______________________________
>> CUSTOMER EMAIL ADDRESS: 
>> patirck@
>> 
>> CUSTOMER INQUIRY:
>> I am trying to verify what the minimum outdoor airflow rate required for EAc1 is and am not sure if this requires a CIR. 
>> 
>> 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. 
>> 
>> 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? 
>> 
>> 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. 
>> 
>> 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. 
>> 
>> 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. 
>> 
>> 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.
>> _______________________________________________
>> 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
> 
> 
> Martin Roy, ing. PA LEED®, président
> Martin Roy et associés
> 1805 chemin Oka, 
> Deux-Montagnes, Qc
> J7R 1N3
> 
> 
> Tel: 450-623-0340
> Cell. 514-594-6352
> 
> www.mra.qc.ca
> 
> 
> 
> 
> 
> 
> Message de confidentialité 
> 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. 
> 
> Devez-vous vraiment imprimer ce courriel ?  Pensons environnement...
> 
> 
> 
> From: "Sachin Sharma" <sachin5787 at gmail.com>
> Date: November 16, 2011 2:55:12 AM PST
> To: "'bldg-sim at lists.onebuilding.org'" <Bldg-sim at lists.onebuilding.org>
> Subject: [Bldg-sim] EnergyPlus: Outlet Nodes not matching error
> 
> 
> Hi,
>  
> I am getting the below error, I have checked the inlet and outlet nodes of all the branches and components, all node names are matching but still I am getting this error.
>  Is it that I am making a fundamental error? Please suggest how to rectify it.
>  
> <image001.png>
>  
> Thanks,
>  
> With regards,
>  
> Sachin Sharma
> M.Tech Energy Engg.
> Department of Mechanical Engineering
> NIT Jaipur
> +91 9983912512
>  
> 
> 
> 
> From: "Patrick J. O'Leary, Jr." <poleary1969 at gmail.com>
> Date: November 16, 2011 4:13:53 AM PST
> To: bldg-sim at lists.onebuilding.org
> Subject: Re: [Bldg-sim] usgbc response to outdoor air question
> 
> 
> imagine a building with 100% oa and evaporatively cooled ... 10 eac1 points ... unless you're gbci reviewer who doesn't understand evap cooling
> 
> On 11/15/11 8:15 PM, Martin Roy ing. LEED AP wrote:
>> Ouch!
>> 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.
>> 
>> Martin
> 
> 
> 
> 
> 
> From: "Jim Dirkes" <jim at buildingperformanceteam.com>
> Date: November 16, 2011 5:53:12 AM PST
> To: "'Martin Roy ing. LEED AP'" <martin.roy at mra.qc.ca>, "'Reba Schaber'" <Rschaber at PHMECH.com>
> Cc: equest-users at lists.onebuilding.org, "'bldg-sim at lists.onebuilding.org'" <Bldg-sim at lists.onebuilding.org>
> Subject: Re: [Bldg-sim] usgbc response to outdoor air question
> 
> 
> While ASHRAE 90.1 does a pretty good job of defining higher efficiency practices, it’s not perfect.  On the other hand, that’s why Appendix G is there; you can show why your idea is better, at least on the energy part of things.
> There are still issues with the general level of knowledge among both the reviewer community as well as the energy modeling community, and that may never cease.  As is commonly the case, a designer often is facing either (energy efficiency) / or (greater IAQ & productivity).  The challenge is how to get the best combination of both.
> One benefit of LEED certification seems to have been that many engineer designers have responded to the challenge of greater efficiency and performance and changed their standard designs in favor of something with better performance.  That’s probably very good, largely because stagnation is never good.
> There certainly is experimentation going on, not all of which is producing great results, but I still prefer a real attitude of “continuous improvement” over stagnation!
>  
> The Building Performance Team
> James V. Dirkes II, P.E., BEMP , LEED AP
> 1631 Acacia Drive NW
> Grand Rapids, MI 49504
> 616 450 8653
>  
> From: Martin Roy ing. LEED AP [mailto:martin.roy at mra.qc.ca] 
> Sent: Tuesday, November 15, 2011 10:15 PM
> To: Reba Schaber
> Cc: Jim Dirkes; equest-users at lists.onebuilding.org; 'bldg-sim at lists.onebuilding.org'
> Subject: Re: [Bldg-sim] usgbc response to outdoor air question
>  
> Ouch!
> 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.
> 
> Martin
> 
> 
> At 21:41 15/11/2011, Reba Schaber wrote:
> 
> Content-Language: en-US
> Content-Type: multipart/alternative;
>          boundary="_000_FAA9B7F58E5E4A46BDDF900F4CCAC3FE03ABA763DD3DPHSERVERphm_"
> 
> RE:  “. . . can’t find) anything in 621.1 which says that unoccupied ventilation should be zero.”
>  
> I think this requirement comes from the mandatory provisions of 90.1.
>  
> 6.4.3.4.3 Shutoff Damper Controls. Both outdoor
> air supply and exhaust systems shall be equipped with motorized
> dampers that will automatically shut when the systems or
> spaces served are not in use. Ventilation outdoor air dampers
> shall be capable of automatically shutting off during preoccupancy
> building warm-up, cool down, and setback, except
> when ventilation reduces energy costs (e.g., night purge) or
> when ventilation must be supplied to meet code requirements.
>  
> Thoughts??
>  
> Reba
>  
> From: bldg-sim-bounces at lists.onebuilding.org [ mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Jim Dirkes
> Sent: Monday, October 17, 2011 9:32 AM
> To: equest-users at lists.onebuilding.org; 'bldg-sim at lists.onebuilding.org'
> Subject: Re: [Bldg-sim] usgbc response to outdoor air question
>  
> Dear Patrick,
>  
> 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 am going to change a couple of things J.
> 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!
> 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.)
> All in all, I’m smarter than I was as a result of your post, so it’s a good day!  Thanks again.
>  
> The Building Performance Team
> James V. Dirkes II, P.E., BEMP , 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 Patrick J. O'Leary, Jr.
> Sent: Monday, October 17, 2011 11:46 AM
> To: equest-users at lists.onebuilding.org; bldg-sim at lists.onebuilding.org
> Subject: [Bldg-sim] usgbc response to outdoor air question
>  
> 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.
> 
> 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.
> 
> regards,
> patrick
> 
> [Fwd: Case 00531150: General LEED Questions
> 
> -------- Original Message --------
> Subject:
> 
> Case 00531150: General LEED Questions [ ref:00D49UeD.5004GN692:ref ]
> Date:
> 
> Mon, 17 Oct 2011 06:54:51 +0000 (GMT)
> From:
> 
> "No reply GBCI" <no-reply at gbci.org> <no-reply at gbci.org>
> To:
> 
> patrick@
> 
>  
> Dear Patrick,
> 
> Thank you for contacting the Green Building Certification Institute. 
> 
> 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.
> 
> 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.
> 
> The following generic LEED Review Comment applies to ventilation systems that do not have demand controlled ventilation:
> 
> 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).
> 
> 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. 
> 
> The following generic LEED Review Comment applies to ventilation systems that do have demand controlled ventilation:
> 
> 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).
> 
> 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. 
> 
> The following generic LEED Review Comment addresses energy recovery in EAc1 energy models as it relates to ventilation systems.
> 
> 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. 
> 
> I hope that helps, but if you have any further questions or concerns, please feel free to use the contact form at http://www.gbci.org/contactus and select "Follow up to GBCI Response," inputting your case number from this email's subject line.
> 
> Best Regards,
> 
> Dan Katzenberger, P.E., CEM, BEMP, LEED-AP BD+C
> 
> Green Building Certification Institute 
> 2101 L Street NW, Suite 500 
> Washington, DC 20037 
> 800-795-1746 (phone)
> 202 828-5110 (fax) 
> www.gbci.org/contactus
> 
> 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.
> 
> 
> _______________________________
> CUSTOMER EMAIL ADDRESS: 
> patirck@
> 
> CUSTOMER INQUIRY:
> I am trying to verify what the minimum outdoor airflow rate required for EAc1 is and am not sure if this requires a CIR. 
> 
> 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. 
> 
> 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? 
> 
> 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. 
> 
> 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. 
> 
> 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. 
> 
> 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.
> _______________________________________________
> 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
> 
> Martin Roy, ing. PA LEED®, président
> Martin Roy et associés
> 1805 chemin Oka, 
> Deux-Montagnes, Qc
> J7R 1N3
> 
> 
> Tel: 450-623-0340
> Cell. 514-594-6352
> 
> www.mra.qc.ca
> 
> 
> 
> 
> 
> 
> Message de confidentialité 
> 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. 
> 
> Devez-vous vraiment imprimer ce courriel ?  Pensons environnement...
> 
> 
> 
> From: Linda Lawrie <linda at fortlawrie.com>
> Date: November 16, 2011 5:56:23 AM PST
> To: "Sachin Sharma" <sachin5787 at gmail.com>
> Cc: Bldg-sim at lists.onebuilding.org
> Subject: Re: [Bldg-sim] EnergyPlus: Outlet Nodes not matching error
> 
> 
> Send your input file to the helpdesk: http://energyplus.helpdesk.com
> 
> The BldgSim list is not a list to supply EnergyPlus support.
> 
> Linda
> EnergyPlus Development Team
> 
> At 03:55 AM 11/16/2011, Sachin Sharma wrote:
> 
>> Hi,
>>  
>> I am getting the below error, I have checked the inlet and outlet nodes of all the branches and components, all node names are matching but still I am getting this error.
>>  Is it that I am making a fundamental error? Please suggest how to rectify it.
> 
> 
> 
> From: Jeremy Poling <Jeremy.Poling at transwestern.net>
> Date: November 16, 2011 7:28:10 AM PST
> To: Reba Schaber <Rschaber at PHMECH.com>, Jim Dirkes <jim at buildingperformanceteam.com>, <equest-users at lists.onebuilding.org>, "bldg-sim at lists.onebuilding.org" <Bldg-sim at lists.onebuilding.org>
> Subject: Re: [Bldg-sim] usgbc response to outdoor air question
> 
> 
> There was an earlier discussion on the list about this:
>  
> 62.1-2007, Section 5.4 states “Mechanical ventilation systems shall include controls, manual or automatic, that enable the fan system to operate whenever the spaces served are occupied.  The system shall be designed to maintain the minimum outdoor airflow as required by Section 6 under any load condition.”
>  
> 62.1-2007, Section 6.2.6.1 states “Ventilation systems shall be designed to be capable of providing the required ventilation rates in the breathing zone whenever the zones served by the system are occupied, including all full- and part-load conditions.”
>  
> These are generally applied to mean that the system is not required to operate when spaces are unoccupied.  Yes, the standard does not explicitly state that unoccupied ventilation should be zero but the standard does not explicitly state that unoccupied ventilation can’t be zero.  Section 5.4 and 6.2.6.1 only require controls and ventilation rates “whenever the spaces/zones served by the system are occupied” so it can be implied that the requirement doesn’t apply when the spaces/zones are unoccupied.  There’s a fine interpretive line there, but many of the official interpretations on 62.1 also lean this direction.  If in doubt, put in an official interpretation request specifically on this with ASHRAE on the topic to clarify.
>  
> 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 Reba Schaber
> Sent: Tuesday, November 15, 2011 8:42 PM
> To: Jim Dirkes; equest-users at lists.onebuilding.org; 'bldg-sim at lists.onebuilding.org'
> Subject: Re: [Bldg-sim] usgbc response to outdoor air question
>  
> RE:  “. . . can’t find) anything in 621.1 which says that unoccupied ventilation should be zero.”
>  
> I think this requirement comes from the mandatory provisions of 90.1.
>  
> 6.4.3.4.3 Shutoff Damper Controls. Both outdoor
> air supply and exhaust systems shall be equipped with motorized
> dampers that will automatically shut when the systems or
> spaces served are not in use. Ventilation outdoor air dampers
> shall be capable of automatically shutting off during preoccupancy
> building warm-up, cool down, and setback, except
> when ventilation reduces energy costs (e.g., night purge) or
> when ventilation must be supplied to meet code requirements.
>  
> Thoughts??
>  
> Reba
>  
> From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Jim Dirkes
> Sent: Monday, October 17, 2011 9:32 AM
> To: equest-users at lists.onebuilding.org; 'bldg-sim at lists.onebuilding.org'
> Subject: Re: [Bldg-sim] usgbc response to outdoor air question
>  
> Dear Patrick,
>  
> 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 am going to change a couple of things J.
> 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!
> 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.)
> All in all, I’m smarter than I was as a result of your post, so it’s a good day!  Thanks again.
>  
> The Building Performance Team
> James V. Dirkes II, P.E., BEMP , 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 Patrick J. O'Leary, Jr.
> Sent: Monday, October 17, 2011 11:46 AM
> To: equest-users at lists.onebuilding.org; bldg-sim at lists.onebuilding.org
> Subject: [Bldg-sim] usgbc response to outdoor air question
>  
> 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.
> 
> 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.
> 
> regards,
> patrick
> [Fwd: Case 00531150: General LEED Questions
> 
> -------- Original Message --------
> 
> Subject:
> Case 00531150: General LEED Questions [ ref:00D49UeD.5004GN692:ref ]
> 
> Date:
> Mon, 17 Oct 2011 06:54:51 +0000 (GMT)
> 
> From:
> "No reply GBCI" <no-reply at gbci.org> <no-reply at gbci.org>
> 
> To:
> patrick@
> 
>  
> 
> Dear Patrick,
> 
> Thank you for contacting the Green Building Certification Institute. 
> 
> 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.
> 
> 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.
> 
> The following generic LEED Review Comment applies to ventilation systems that do not have demand controlled ventilation:
> 
> 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).
> 
> 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. 
> 
> The following generic LEED Review Comment applies to ventilation systems that do have demand controlled ventilation:
> 
> 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).
> 
> 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. 
> 
> The following generic LEED Review Comment addresses energy recovery in EAc1 energy models as it relates to ventilation systems.
> 
> 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. 
> 
> I hope that helps, but if you have any further questions or concerns, please feel free to use the contact form at http://www.gbci.org/contactus and select "Follow up to GBCI Response," inputting your case number from this email's subject line.
> 
> Best Regards,
> 
> Dan Katzenberger, P.E., CEM, BEMP, LEED-AP BD+C
> 
> Green Building Certification Institute 
> 2101 L Street NW, Suite 500 
> Washington, DC 20037 
> 800-795-1746 (phone)
> 202 828-5110 (fax) 
> www.gbci.org/contactus
> 
> 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.
> 
> 
> _______________________________
> CUSTOMER EMAIL ADDRESS: 
> patirck@
> 
> CUSTOMER INQUIRY:
> I am trying to verify what the minimum outdoor airflow rate required for EAc1 is and am not sure if this requires a CIR. 
> 
> 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. 
> 
> 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? 
> 
> 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. 
> 
> 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. 
> 
> 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. 
> 
> 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.
> 
> 
> 
> From: Sandor Rosta <srosta at swinter.com>
> Date: November 16, 2011 11:25:49 AM PST
> To: "bldg-sim at lists.onebuilding.org" <bldg-sim at lists.onebuilding.org>
> Subject: [Bldg-sim] HELP WANTED: Energy Modeler SWA (NY-CT)
> 
> 
> Steven Winter Associates, Inc. (SWA) seeks a qualified professional to provide energy analysis for high performance and green buildings, including multifamily, commercial, and institutional buildings. Work will primarily focus on energy modeling in eQUEST/Energy Plus. Energy modeling will support LEED (Leadership in Energy and Environmental Design) projects nationally, NYSERDA Multifamily Program or New Construction Program projects. Depending on experience and interest, other opportunities may be available in energy auditing services and building performance diagnostics. Opening may be available in either SWA’s New York or Connecticut offices.
>  
> For more information, view the posting on our web site:
> http://www.swinter.com/da44e168-725f-4ea5-9b89-9fd91e8ebb31/about-us-careers-details-nyc.htm
>  
>  
> Thanks
> Sandor Rosta
> Senior Mechanical Engineer, LEED AP
> 212.564.5800 x125 (direct)
> 212.741.8673 (fax)
> srosta at swinter.com
>  
>  
> 
> ______________________________________________________________________
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