How to ventilate basement?

[abhi_w92]

I have an upcoming small commercial gym in a basement, and the interior work is yet to be done. I am concerned about lack of ventilation as the basement is a little suffocating and humid. What kind of cost effective solutions can be there to avoid suffocation when about 15-20 people are sweating at the same time. There is a very small pipe used as an outlet towards the street but I don't think it would be effective exhaust for the entire basement alone.

[Strongblood]

Proper ventilation in basements is very important. Not only for moisture and mold but possible carbon monoxide poisoning. In the wintertime if you use any kind of space heater be especially careful because the heater can use up the oxygen in the room very fast (especially with a gas heater!)causing everyone in the room to go to sleep and not wake up.
As far as fixing your ventilation issue, most small to moderately sized basements, a ventilation fan on one side of the basement and an exhaust fan on the other end is suitable the fans need to be permanently installed within existing window cavities, or you may need to cut openings through the portions of the basement walls that are above ground. The best ventilation fans include a humidity sensor for simple automation. Once the sensor detects a certain moisture content, the fans vent the air until the moisture content in the basement is reduced. These types of mechanical ventilation are not that expensive and will save you money down the road. Hope this helps.

[Beetlegeuse]

Something I would add is that the intake for your exhaust fan should be located as high as possible (if you have a choice). Both carbon monoxide and humid air are lighter than dry air, so an exhaust vent up high covers both bases.

I know it sounds counter-intuitive, being that water is heaver than air, but when you add water vapor to air, the air actually gets lighter. That's because the vapor pressure of water vapor is much higher than for dry air. Once it's a gas, the high-pressure water molecule expands until its vapor pressure equals the pressure of the dry air that surrounds it. By which time the water vapor molecule is taking up so much space it has lower density than dry air, which means it rises and dry air sinks. In fact, that's why steam engines work the way they do. Because when you convert water to steam, the steam wants to take up so much space that it's willing to (and strong enough to) push the piston or the turbine in order to get it.


Strongblood already brought up my Part B. When the exhaust fan sucks the bad air out of your room, where is the replacement air (the "good" air) going to be coming from? Ideally, and especially with a wimpy exhaust fan, you'll have a better result if there's a second duct to a better air source, better still if there's something forcing good air into the room.

And even with a small air duct, you still can get a high flow rate, but there'll be more noise as a consequence.