I'm not sure how fresh air, or oxygen, gets inside my house other than through cracks of window or door on a cold winter day when the central heating system is on.

I have a pipe that is coming from outside in my basement and delivers air to my basement (there is no fan in it or anything just a pipe by itself). And I think that is meant for providing fresh oxygen for the gas furnace to burn. However, since it is not directly connected to the furnace air intake vent ( a white J-shaped pipe), there will be some outside fresh air delivered to my basement, but in no way is that an effective way of delivering fresh air to the whole house.

So I'm asking this question because sometimes I feel suffocated even when the central fan is on in my house, and I have already positioned myself to be near the vents to make sure there are air flowing around my head. I can't really open the window because my window is facing a neighbor who constantly burns his wood in his old fashioned furnace when produces black smoke that blows towards my window. Our basement outside air intake place is somewhat more discrete, though. Which is why I'm not smelling smoke when all windows are closed.

So I'm asking, is there no other way of getting fresh air inside my fresh air, by using the furnace? Or is an average house supposed to be have fresh air intake systems? I'm in no way an HVAC expert, I might be making wrong presumptions in my question, but any help would be appreciated :)

  • 1
    Do you have a carbon monoxide sensor in the house? Since you have gas heat you should have one to warn you if a fault in the furnace is introducing deadly Carbon Monoxide gas into your house. Here's a fact sheet about carbon monoxide poisoning
    – Johnny
    Jan 22, 2016 at 0:08

4 Answers 4


It depends on the home, and the system. Neither of which you've provided much information.

Older homes are usually drafty enough to provide adequate combustion air, so dedicated intake are not required. Modern homes tend to be sealed up much tighter, and often require air intakes.

Sometimes systems are installed in a utility closet, or other space where makeup air can't be drawn from surrounding areas in the home. In these cases, an air intake will also be used.

Some modern furnaces actually draw air from outside, directly into the unit. This reduces the amount of cold dry air that is pulled into the home.

If you're simply concerned about the quality of the air entering the home, it's possible that you could install a filter on the intake. Though you'll have to make sure you don't restrict the amount of air being drawn in.

If you don't have carbon monoxide detectors in the home, you'll want to install some.


Old houses leak like crazy and that, alone was typically more than enough to provide both fresh air and combustion air. On new construction, an air exchange handler is the typical way to provide fresh air.


From your comments, I don't believe your question is out of concern for your heater, but for yourself. But, to be sure, if your heater is less that about 20 years old, it probably has its own dedicated intake from outside the house for combustion. If it is older, it may draw on air from onside the house. Either way, by design, combustion air is never mixed with the air you breathe, for obvious reasons.

That said, in most houses the air you breathe is only renewed by leakage and opening and closing of doors, so the tighter your house (read: newer your house), the less outside air will get inside.

I'm not aware of any great way to fix this, since getting that "fresh" outside air into your house means significant loss of the warm or cool air and the energy dollars you spend to get it that way. I have read about small heat exchanger systems that help offset that loss, but I believe their effect is minimal. In my home, we simply open up the house about once a week and let new air come in. We figure the cost will be offset by fewer doctor visits and less pain and suffering from sickness. ope that helps!

  • 1
    I don't see an answer to the question this is more of a comment.
    – Ed Beal
    Mar 8, 2017 at 13:59

The Building Code requires, in most commercial buildings, to have outside air mixed with return air from the building spaces. (Some exceptions exist for buildings with operable windows.) For residential buildings, operable windows are "designed" into the building, (I.e.: required egress windows in bedrooms, etc.) In addition, fresh air is brought into the house by infiltration, (leaks around windows and doors,) and by traffic, (people coming and going) in and out of the house.

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