Hope you don't mind me quoting you separately - but it is the only to logically answer this.
Originally Posted by
Michael Thomas
"Outdoor and return air for a forced-air heating or cooling system shall not be taken from... 3. A room or space, the volume of which is less than 25 percent of the entire volume served by such system. Where connected by a permanent opening having an area sized in accordance with ACCA Manual D, adjoining rooms or spaces shall be considered as a single room or space for the purpose of determining the volume of such rooms or spaces."
Looks like the basement has to be considered separately from "adjoining areas or spaces" (the first and second floors)" as the door is not a "permanent opening".
The attic is not conditioned space, and thus not served by the system. In my area the typical basement ceilings in older homes are around 6 '6", and the typical ceiling elsewhere is around 8', so the basement volume is around 28% of the volume served, and the 10' rule does not apply under (3) above.
That puts the basement at over 25% based on your calculations, thus 3. does not apply, but that does not remove 1. from the equation. EACH of those conditions is taken separately as stated in each condition.
"- 3... Exception:The minimum volume requirement shall not apply where the amount of return air taken from a room or space is less than or equal to the amount of supply air delivered to such room or space."
If I'm reading this correctly, you could have a return cut into a duct adjacent to a draft hood as long as you had supply registers in the basement providing a greater amount of air at the far ends of the basement, even if the basement is less than 25% of the total volume, which lead us to:
Nope.
First, you are trying to apply different requirements and intermingle them with each other. Apply each separately.
Second, are you even allowed to draw return air from the basement? Is the basement insulated and part of the thermal envelope? If not, drawing return air from the basement would be drawing unconditioned air into the system, which would require additional heating or cooling (and probably dehumidification) to get the 'return air' to be compatible with the 'environmental air' in the conditioned space. Also, is it even 'return air' if no 'supply air' is provided? Would it not be just 'additional air', such as 'outside air', in which case, where would the 'return air' be located?
Are your basements insulated and part of the thermal envelope of the house?
Are your basements 'conditioned'? Or, are they like the attic, just 'separated from' the conditioned space?
I remember (vaguely) the basement of the house we had in New York (40 miles south of Buffalo) and I recall the basement being much colder than the living space above - not freezing cold, just much colder, like it was not heated, but the earth insulated some of the cold out and the heated area above provided some heat through the floor into the basement. But I was young then (we moved to Florida when I was 10) and my memory might be off.
"from... 4. A closet, bathroom, toilet room, kitchen, garage, mechanical room, furnace room or other dwelling unit. "
The entire basement serves as the "furnace room", but... is this intended to apply in such situations, or rather to something like an enclosed utility closet within a basement or other "unconfined space"?
First, is the basement part of the conditioned space (see questions above)?
If yes, then I would treat the basement like a mechanical room, furnace room, or even a garage (similar things may be stored in a basement, depending on the basement and access to outside).
If no, then should you be taking 'return' air from the basement anyway?
"From ... A room or space containing a fuel-burning appliance where such room or space serves as the sole source of return air."
Typically, there will be return air ducted from rooms above, so this would not seem to apply either...
But are there "returns" from the basement? Are there "supplies" to the basement?
So, assuming that the basement is 25% or more of total volume, what prohibits someone from putting a big honking return grill in the return plenum at the furnace?
Or even assuming it's smaller, what prohibits someone form putting a smaller return opening there if the supply to the basement is greater than the return volume at the grill?
See my above questions and answers (more questions than answers, though).