BOILER ROOM EXHAUST
In a 2 family home, does the actual boiler room containing boiler, hot water heaters, and hvac equipment need to be vented outside ? the boiler and hot water heaters are currently vented through the chimney to the roof.
In a 2 family home, does the actual boiler room containing boiler, hot water heaters, and hvac equipment need to be vented outside ? the boiler and hot water heaters are currently vented through the chimney to the roof.
Actually, it gets kind of complicated.
Most states subscribe to, or paraphrase, NFPA-54 also known as ANSI
Z-223.1 or the National Fuel Gas Code.
That states (in shorthand) one square inch of CLEAR FREE NET AREA per 4,000 BTUH input if the openings are vertical or directly communicate to the outside. If you duct horizontally any distance, it has to be 1 square inch per 2,000 BTUH input (doubles the area).
If you take the air entirely from indoors, I think the rule is 50 cubic feet of open volume per 1,000 BTUH input. If the room is
isolated from the total volume, this means is a no-go.
Also, The BTUH input is based on all appliances in the space, not just those which normally run.
So, if you’ve got the capability to burn 200,000 BTUs at once (boiler, water heater, clothes dryer, etc.) in your cellar, you’ll need 10,000 *cubic* feet (not square feet) of open space to legally get away with not ducting in some fresh make up air.
Most people don’t have it.
So then you’ll have to make up a duct with an opening up high and another down low that measures 200 square inches (20†x 10â€), connects directly to the boiler area and terminates unobstructed to the fresh air outside.
As I said, it gets complicated, but this should give you an idea.
Hope this helps.
You need a grille or a simple opening of approx 12″ X 12″ that allows fresh air into the cellar to replace the oxygen that is being burned up by the gas burning utilitities. The duct you refer to that is venting the boiler & h.w. heater to the chimney/roof is carrying the Carbon monoxide to the exterior.
Master Plvmber, what would qualify as an opening to the outside air? As far as I know in my basement there is no opening for air intake, but maybe I just don’t know what I’m looking for.
The room doesn’t need to be “vented”. It needs replacement (or make-up) air to allow for the effective venting of the fuel-burning appliances.
That’s to replace the air in the building that goes out the chimney when the boiler’s running
So, yes, it needs an opening to the outside air.
Unless of course you’ve got something called sealed combustion or class III venting equipment, which you probably don’t.