Return air ducts should generally not be installed in rooms with high humidity, contaminants, or strong odors. This includes bathrooms, kitchens, garages, closets, attics, and furnace or boiler rooms. Placing vents in these areas can draw moisture, fumes, odors, and potentially hazardous gases like carbon monoxide into your HVAC system, which can damage ductwork, promote mold growth, and compromise your home's indoor air quality and safety. According to the International Code Council, there are some exceptions. For example, a return duct may be placed in a kitchen if it is at least 10 feet away from cooking appliances and serves only that room. Similarly, a garage can have a return duct if it is part of a dedicated forced-air system that only serves the garage. For optimal performance, prioritize installing return air vents in central locations and rooms with consistent temperature needs, such as bedrooms and living spaces. If you are unsure, consult a professional duct installer for guidance.

To get water out of AC vents, first identify the source of the water. Check other air vents in your home for signs of moisture. If you can’t find any, look around the room for anything that might have seeped water in like an overwatered plant or a spill. Meanwhile, if you notice more than one air vent wet in other areas of your home, it’s more than likely an issue with your insulation, roof, or air conditioner. Start by hiring an HVAC technician who can trace the source of the leak for you.

In most homes, your chimney and HVAC are separate from each other. However, you can use your chimney to save on heating costs in the winter. Turn off your HVAC system and start a cozy fire, then watch the electric bills drop during the coldest months. Make sure your flue is closed when not in use so that you don’t end up pumping heat or cool air from your system outside.

Whether air duct cleaning is worth the cost depends on your specific situation. While it hasn't been proven to prevent health issues, it can be beneficial for improving indoor air quality by reducing contaminants, which is especially important for households with members who have asthma or allergies. Cleaning is generally considered worthwhile if you notice visible mold growth, signs of a pest infestation, excess dust, or debris blowing from the vents. It is also recommended after a major home renovation. Additionally, if your ducts are dirty enough to leak air, cleaning and sealing them can improve your HVAC system's efficiency, ensuring the heated or cooled air reaches your living spaces and potentially leading to long-term savings.