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Ashrae 62.1
- Thread starter gbhammer
- Start date
mtlogcabin
SAWHORSE
What code section requires it
IMC 403.2 requires outdoor air, and T403.3 is over the top restrictive, so some mechanical engineers try to bring the cfm's down with ASHRAE 62 as allowed for in IMC 105. The problem is that the documentation requirements are excessive.mtlogcabin said:
mtlogcabin
SAWHORSE
The numbers in T403.3 are minimum and you can't lower them through any means.
mtlogcabin
SAWHORSE
My 
Well then do you require an engineer to provide electrical calculations for what they design, or the structural engineer theirs? That is basically what you would be receiving. I would think a note on the stamped and signed plans indicating the ventilation is designed in accordance with ASHRE 62.1 would suffice. How about having them provide a Table similar to 403.3 indicating the "designed" cfm rates for the different occupancies. Remember it is a system that you have no way of knowing if it will work properly or not so why worry about all the details
Well then do you require an engineer to provide electrical calculations for what they design, or the structural engineer theirs? That is basically what you would be receiving. I would think a note on the stamped and signed plans indicating the ventilation is designed in accordance with ASHRE 62.1 would suffice. How about having them provide a Table similar to 403.3 indicating the "designed" cfm rates for the different occupancies. Remember it is a system that you have no way of knowing if it will work properly or not so why worry about all the details
RJJ
Co-Founder
And how many calculations does it take to cover that? 
RJJ
Co-Founder
:cheersLoL!
rgrace
Sawhorse
Okay folks, I'd like to reopen this thread and see if we can have some more intellectual discussions about this. In my opinion, gbhammer was most certainly on the right track with their opening statement. Where a design professional chooses to reduce the minimum outdoor air rates from IMC Table 403.3, it is the responsibility of the code professional to verify compliance to those alternative methods, not just allow a simple note on the plans that states "I comply". BTW, in my juristiction, we do require electrical, mechanical, plumbing, and structural calculations, and we review them all for compliance to the applicable codes.
First, the codes. The 2009 International Existing Building Code references ASHRAE 62, Indoor Air Quality (IAQ) Procedure in section 709.2. The 2009 International Mechanical Code indirectly references ASHRAE 62, IAQ Procedure in section 403.2 (exception) by stating “where a RDP demonstrates that an engineered ventilation system will prevent the maximum concentration of contaminants from exceeding ….” These code sections will allow the use of ASHRAE 62 IAQ procedure.
Now the questions. 1- Are gbhammer and myself the only ones who have been approached by an air filtering manufacturer (or design professional) requesting to use this procedure (as a selling point for their product)? 2- Are gbhammer and myself the only ones asking for the documentation required to accurately evaluate this procedure? This procedure will attempt to significantly reduce the minimum outdoor airflow rates provided in IMC Table 403.3.
Food for thought … direct quotes from AHSRAE 62.1-2007 Appendix B
“At present, no single organization develops acceptable concentrations or exposures for all indoor air contaminants, nor are values available for all contaminants of potential concern.”
In reference to Tables B-1 and B-2, “Meeting one, some, or all of the listed values does not ensure that acceptable indoor air quality will be achieved.”
In reference to Table B-2, “ASHRAE does not recommend their adoption as regulatory values, standards, or guidelines.”
First, the codes. The 2009 International Existing Building Code references ASHRAE 62, Indoor Air Quality (IAQ) Procedure in section 709.2. The 2009 International Mechanical Code indirectly references ASHRAE 62, IAQ Procedure in section 403.2 (exception) by stating “where a RDP demonstrates that an engineered ventilation system will prevent the maximum concentration of contaminants from exceeding ….” These code sections will allow the use of ASHRAE 62 IAQ procedure.
Now the questions. 1- Are gbhammer and myself the only ones who have been approached by an air filtering manufacturer (or design professional) requesting to use this procedure (as a selling point for their product)? 2- Are gbhammer and myself the only ones asking for the documentation required to accurately evaluate this procedure? This procedure will attempt to significantly reduce the minimum outdoor airflow rates provided in IMC Table 403.3.
Food for thought … direct quotes from AHSRAE 62.1-2007 Appendix B
“At present, no single organization develops acceptable concentrations or exposures for all indoor air contaminants, nor are values available for all contaminants of potential concern.”
In reference to Tables B-1 and B-2, “Meeting one, some, or all of the listed values does not ensure that acceptable indoor air quality will be achieved.”
In reference to Table B-2, “ASHRAE does not recommend their adoption as regulatory values, standards, or guidelines.”
GBrackins
REGISTERED
Welcome to the Forum rgrace!
rgrace
Sawhorse
Thank you, Gary. I've here before (as evident of my join date), but due to technical issues that frustrated me, I gave up :/ On a whim, I came back for another try and after a few days of conversing with the webmaster, I was able to join again 