IMC 2015 and ventilation of dwelling units

[carlosgw]

International Mechanical Code - 2015
Ventilation for residential buildings over 3 stories vs. 3 stories and less.

The way I read IMC 403.1 is for a 4 story or higher residential building - because it is covered under the commercial energy code and not the residential energy code - is that natural ventilation can be used. 

The paragraph says specifically "when tested ..... in accordance with Section R402.4.1.2 of the IECC" which as far as I can tell does not apply for residential over 3 stories.

This is a literal interpretation. Am I missing something?

I personally think that it (the above interpretation) does not comply with the spirit of the code. And a four story building should be as tight if not tighter than a 3 story building (I think).

 

[GT-EGR]

I think you are mixing up how the energy code applies.

Energy code doesn’t dictate whether or not you have to use natural or mechanical ventilation - it only dictates the energy considerations of the system you end up choosing.

If IMC is your governing code - then you just have to follow and meet chapter 4 requirements, and right in the beginning it points you to the two acceptable methods saying you can either naturally or mechanically ventilate. I’m fairly certain it doesn’t get specific about building type or usage.

 

[carlosgw]

Thanks.
It (2015 IMC) actually does get specific for dwelling units.