Many apartments require all windows to be closed during winter when the heating is on. But even when the apartments have central heating, as far as I know about my current apartment, it just circulate the air inside the apartments, and doesn't bring in fresh air.

It is dangerous to tenants' lives that the CO2 and other kinds of gas become accumulated inside. So are the above policies of apartment managers reasonable?

As tenants, what can we do to guarantee we have necessary fresh air to breath?

An example of such policies is following:

During the heating season when the outside temperature is below 50-degrees, all windows must be kept closed to prevent waste. During the winter when the outside temperature is below freezing, leaving a window open, even one inch, can freeze the heat lines beneath the window and cause a flood. Management will watch for open windows and repeat offenses may result in a charge to the Tenant.

  • 1
    Freedom of the press belongs to them what owns the press. Freedom of the windows belongs to them what owns the windows and provides the heat. Commented Dec 11, 2013 at 2:33
  • Whatever you do, don't burn any candles!
    – Tester101
    Commented Dec 11, 2013 at 12:38
  • Do you have forced air heating, or hot water? Question seems to refer to both...
    – DJohnM
    Commented Dec 11, 2013 at 18:41
  • I asked about air heating. @User58220. What do you mean by "forced"?
    – Tim
    Commented Dec 11, 2013 at 20:07
  • 1
    "Forced air" means a fan blowing heated air through duct work to the rooms. The quoted policy seems to refer to pipes carrying heated water...
    – DJohnM
    Commented Dec 11, 2013 at 20:24

2 Answers 2


There are very few workplaces or residences which are so air tight that air cannot exchange with the outdoors adequately. Particularly if an exterior door is opened for a few seconds once in awhile or a heating or cooking appliance exhausts outdoors (thus drawing in outside air). Buildings which are designed to be really airtight will have an outside air intake, usually with a heat exchanger for energy efficiency.

In ordinary construction up to the 1990s, there was little concern of consuming interior oxygen, even with a small apartment and a large number of people visiting, cooking, etc. Doors, walls, windows, floors, closets, plumbing and electrical holes simply were not that tightly sealed.

If this is truly a concern for you, rent or buy an air oximeter. An "inexpensive" laboratory model for O2 is less than $1000 here (a bargain compared to many). Lab instrumentation rental businesses typically require a month or two minimum rental. To get a reasonably complete understanding of the air composition, a model which reads both CO2 and O2 is desirable.


It is dangerous to tenants' lives that the CO2 and other kinds of gas become accumulated inside.

No. It is normal for CO2 levels to be higher in inhabited spaces.

However, there are levels of CO2 that are dangerous. Usually because of other factors such as improperly installed heating systems or inadequately vented kitchens etc. This should not normally be a problem. If in doubt, measure it.

The levels of CO2 in the air and potential health problems are:

250 - 350 ppm – background (normal) outdoor air level
350- 1,000 ppm - typical level found in occupied spaces with good air exchange.
1,000 – 2,000 ppm - level associated with complaints of drowsiness and poor air.
2,000 – 5,000 ppm – level associated with headaches, sleepiness, and stagnant, stale, stuffy air. Poor concentration, loss of attention, increased heart rate and slight nausea may also be present.
>5,000 ppm – this indicates unusual air conditions where high levels of other gases could also be present. Toxicity or oxygen deprivation could occur. This is the permissible exposure limit for daily workplace exposures.
>40,000 ppm - this level is immediately harmful due to oxygen deprivation.

Wisconsin dept of health

So are the above policies of apartment managers reasonable?

In my view, yes.

You shouldn't pay your apartment owners to heat the outside air. You should pay them to heat the interior of your apartment.

There is also the consideration of harm to the environment, but I know that's not a concern in some cultures.

If you measure over 1000 ppm CO2, and are certain it's due to factors beyond your control (e.g. not due to burning candles etc) you have good cause to ask the building owner to do something about it.

The Wisconsin "normal" levels are actually low and may be out of date. Outside CO2 levels rise in winter (and probably near roads etc) and are probably rising year on year.

enter image description here US DOE CDIAC

So don't be alarmed if your outside CO2 levels are substantially higher than "250-350 ppm". That's a global problem, not a problem with your particular home.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.