Combustible Air

Tom M

When people finish basements and close in boiler areas they are confining the air supply needed to feed the flow of fuel burning. So although you can bring in additional air from the other rooms or outside many dont. My question would be if you have a pilot and flame then why isnt it good enough. Is it in-efficency? Working harder than it needs to and cost more to run? Is this the logic here?

thom

Your question isn't clear. Are you asking if the pilot and or flame are present is that not evidence of adequate draw? If that's the question, the answer is obviously, no.

Tom M

You can have flame and not nearly enough combustible air what are the consequences? Im curious. MOST older homes dont have enough air yet there are no problems.

Hurley

Without enough free air you're gonna run into two problems if yu have an atmospheric boiler and if there's a pilot that's what you got. One is incomplete combustion which is inefficient combustion. That means carbon and soot clogging the heat exchanger and vent. Two is potentialy dangerous. The flame will pull air from anywhere it can including down the vent which means eventually CO2 will begin spilling into your home.

#CARRIERMAN

Hi tom m

Hurley is right on the money. With inadeqaute combustion air there is a potential for flame rollout as well as sooting. Both are potentially very dangerous. The one thing most people forget is accomodating flue draft. Most people are only concerend about proper air for combustion. But think about it in the human sense, what goes in must be able to come out or there will be problems.

Good luck
Rusty

Tom M

Thanks guys well put I see the senerios here. Im not a Hvac guy Im just looking out for situations they do come up. Where will I see carbon or soot build-up that will tell me there is trouble. I cant see into the vent connectors, other than a black air filter on the heat exchanger what should I look for.

Glasshousebltr

tom m you devious devil .....I think it's evident the little lady's making you build a fart room in the basement.

Bob

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Bob

#CARRIERMAN

Hi tom m

You will usually be able to see the first signs of sooting in the draft diverter for the flue, there will be a discoloration inside the flue pipe that sometimes protrudes to the outside of the pipe. The second place will be the burner compartment, you will start seeing black chunks under and on top of the burners. These are just things to look for, these are pointers I am giving, this does not mean that your boiler is sooted up at this point.

Good luck
Rusty

Double-A

Carrierman hit on the second most overlooked aspect.

You need dilution air for drafting as well as combustion air for any carbon-based fueled appliance.

In answer to your 'older home' question, the older homes were less air-tight in construction, so air was able to move from outside to inside or from floor to floor with ease, so the problem was not as serious as it can be in a more air-tight home. I would size my dilution and combustion air as though this house were air-tight in all cases. You can't have too much air available for efficient combustion and proper draft.

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