A utility closet, basement or garage are all suitable locations for an HVAC unit. However, installing a system in these locations could reduce your square footage of living and storage space. Some property owners would rather use closet space to store personal items, and if finishing the basement, they may prefer keeping the HVAC unit out of sight. An HVAC unit kept in the garage can also decrease storage space and perhaps impact the ability to easily park one or more vehicles.
HVAC systems typically produce noise as they turn on and off. If you keep the HVAC unit in a closet near the family room or living room, the noise from the unit might interrupt television programs or conversations, wherein you're forced to turn up the volume or speak louder. Keeping the HVAC unit in the attic could alleviate this issue. The attic walls are insulated and this insulation reduces excess noise.
Installing HVAC units in the attic could also protect the unit from water damage. HVAC units are costly to repair and replace. In the event of flooding from a burst water heater, broken pipe or storm surge, HVAC units kept in the garage, basement or a ground floor closet may sustain water damage. Attic installation keeps the unit off the main floor and away from flood-prone areas.
If you're dealing with limited storage space in your home, and you want to free up space in a closet, the garage or the basement, you can relocate your existing HVAC system to the attic. This is not a do-it-yourself job, and you will need to contact a heating and air conditioning company. The company will assess possible locations in your attic, move the unit, and modify the existing duct work to ensure that each room in your house receives an adequate supply of heat and coolness. The cost of relocating a unit varies. Consult several heating and air companies to discuss your options and compare prices.