For years I have wondered where the best location for an air handler is. When I was growing up as a young child in a northern state, it was unheard of to find an air handler installed in someone’s attached garage. But where I live now, that’s the standard in all new homes being built. Surely there’s a practicality standpoint over the ease of installing the equipment so close to where the actual outside condenser will be located, making repairs easier and requiring less materials and shorter pipes for the refrigerant lines. Regardless, the major issue right away with putting an air handler in an attached garage is energy efficiency. Garages are rarely conditioned spaces and are full of outdoor heat in an environment like mine. Any leaks on the outside of the air handler, however tiny they may be, will all let in air from your garage. If your garage is hot enough, this is a notable area of energy loss. But on the same token, when dealing with the topic of leaks, the more pressing concern isn’t even energy loss, but straight up poisoning. Garages are some the dirtiest environments in a home and often contain paint, solvents, gasoline, oil, and other chemicals that release harmful VOCs into the air. On top of these, you’re also dealing with the carbon monoxide from your car fumes, which will undoubtedly expose your air handler whenever you park in your garage and first power down the car, leaving some fumes trapped in the small space and slowly leaking into your indoor air. For all of these reasons and more, it’s smart to find a location inside the home rather than using an attached garage to house your HVAC air handler.