Hello,
Our building is a multifamily building project and my question is, are we still required to complete the VRP calculations for this prerequisite? Based on the reference guide, it seems VRP calcs are required for compliance, but the engineers on this project believe the VRP calcs are not applicable because the ASHRAE calculations are based on Air Change Method Table E-2a (outdoor air requirements for ventilation of residential facilities, private dwelling, single and multiple) and that is enough. So, are VRP calcs required and if so, how would we have to complete them in our case?
Any advice would be greatly appreciated!
Courtney
Andrew Mitchell, P.E.
PrincipalMitchell Gulledge Engineering, Inc.
LEEDuser Expert
126 thumbs up
August 13, 2013 - 4:31 pm
Courtney, you have me stumped. Where is Table E-2a? Is it in one of the addenda to 62.1-2007?
Courtney Royal
Sr. Sustainability ConsultantTaitem Engineering
50 thumbs up
August 14, 2013 - 10:06 am
Hi Andrew,
This is actually a v2.2 project so we're using ASHRAE 62.1-2004 (seems there is a problem with the website and it won't allow me to post under v2.2). Anyways, nope its not an addenda, its in the standard. If you look under Table 6-1 Min Ventilation Rates for Breathing Zones, at the bottom, you'll see a category for "Hotels, Motels, Resorts, Dormitories." This building is a multifamily building so this table wouldn't necessarily apply. However under the "General Notes" #7 it says that for Residential buildings rates shall be determined with Appendix E. That is where Table E-2a, Outdoor Air Requirements for Ventilation of Residential Facilities comes in. These calculations are definitely not my strong suit, but I guess I am trying to figure out how to take these values and apply them into the VRP spreadsheet. Because that is required even if the building is multifamily or not, correct?
I would appreciate any assistance! Thanks much.
Andrew Mitchell, P.E.
PrincipalMitchell Gulledge Engineering, Inc.
LEEDuser Expert
126 thumbs up
August 14, 2013 - 10:15 am
OK, that helps. I didn't even think to look in 2004. In that case, I would use an alternative compliance method in lieu of the template. Just upload a narrative saying why you are using table E-2a and a calculation sheet to show that you comply with the requirements. USGBC does not specifically require that you perform a VRP calculation, only that you demonstrate compliance with the standard. The VRP is the predominate method but not the only one.
Courtney Royal
Sr. Sustainability ConsultantTaitem Engineering
50 thumbs up
August 14, 2013 - 10:22 am
Thanks a lot, Andrew! That was our original reply to the design team, but then after reading the reference guide again and again, it seemed that VRP were required because it never suggested anything about multifamily residences and i assumed it would have. Thanks again.
Courtney Royal
Sr. Sustainability ConsultantTaitem Engineering
50 thumbs up
August 21, 2013 - 3:47 pm
Ok, I just heard back from GBCI regarding this, and "Appendix E, Table E-2 provides outdoor air requirements for residential facilities. However, this does not preclude the project team from using VRP method. Alternatively, Table E-2 values should be used to complete VRP calculations."
My question now becomes, besides the ACH method values, what other values are needed to complete the VRP calcs? Ez?
The engineer on the project thinks that because its residential and all apts have PTAC units (with no ductwork) that many of the credit requirements don't apply. However, I have confirmed that VRP (or local code) calculations are required but I am not sure exactly which of the values are needed to complete the spreadsheet.
Thanks!