We live in this invisible stuff called air. (But of course you knew that.) We pump it into and out of our lungs. We exhaust it from our bathrooms and kitchens. We cycle it through our heating and air conditioning systems. If we’re lucky, we live in a home that even brings outdoor air inside as part of a whole-house ventilation system. But we’re missing something.
And under what conditions would it move exactly 2.5 tons of air?