Most American homes have a bewildering array of diffusers, registers, and grilles that blow air out or suck air in. For many homeowners, these apertures are somewhat mysterious. We all know that there must be a duct behind each grille, but where does the duct lead?
Ducts are hidden tubes that snake through our buildings. Ducts play a surprisingly important role in many movie plots. Movie makers almost never explain what kind of duct we are looking at; all we know is that the ductwork is always big enough for a person to crawl through, and that the duct usually connects an inconspicuous mop closet with the computer server room of a major corporation or a hallway adjacent to a bank vault.
Does my home have a ventilation system?
It’s useful to have a solid understanding of the function of all these grilles and ducts. Otherwise, you’ll be like one of those homeowners who doesn’t know whether or not his home has a ventilation system. You know — the ones who say, “I turn on the air conditioning and cool air blows out the vents. That’s a ventilation system, right?”
Well, maybe — but probably not.
In this article, I’ll look at most of the grilles, registers, and diffusers in a typical house. First, we’ll determine whether these openings are designed to suck or blow. Then we’ll determine whether the air flowing through the openings is recirculated air or fresh outdoor air. All of this information will be useful if you want to determine whether your home needs a ventilation system.
A window-mounted air conditioner. This is a simple device that blows air into your room. Where does the air come from? Is it…