How to tell which way does air flow on a furnace
If you're standing in your utility closet or basement staring at a metal box, wondering which way does air flow on a furnace, you aren't alone. It's one of those home maintenance questions that seems simple until you're actually holding a new air filter and realize you have a fifty-fifty shot of putting it in backward. Getting this right is a big deal because your HVAC system is basically the lungs of your home. If the "breath" is restricted or moving the wrong way through the filter, things start to get expensive and annoying pretty quickly. ...