Permits and Combustion air - Help!
I was quite happily completing all the paperwork to apply for permits when I hit the form "Combustion Air Worksheet". I'm in NJ but the after a few web searches the rules appear to be pretty standard.
The calculation says to take BTU ratings of all appliances divided by 1000 and times by 50 = Cubic Feet required.
I have two 82K BTU furnaces (one for each floor) and a 75K hot water heater, so:
82 + 82 + 75 = 239 x 50 = 11950 cubic feet.
There are rules about adjoining spaces but I hit a problem before that. Assuming a height of 8ft (which is unlikely in the finished state) that would mean I would need 1494 sq feet of space. My basement isn't that big to start with around 1300 sq ft or raw space.
I've managed to get hold of a few examples of other peoples paperwork and they all appear to be incorrect based on my understanding of the instructions. For example one home only included the BTU rating from one of their furnaces, the other only entered half the rating of the water heater. All the examples seem to be using a height of 8ft when I know the ceilings are lower than that.
Am I doing something wrong? I'm happy to post my plans or anything else if it will help. My plans had the furnaces and water heater in a 17' x 13.5' unfinished area of the basement.