Floor AC Ducts: Pros and Cons

Floor air vent

Considering the installation of air conditioning (AC) ducts under the floor? Every AC installation is a custom job, with a host of variables effecting “best practices” for each location. For those considering the installation of ductwork under the floor as opposed to in attic space, understanding the basics of air flow and the assets and limitations of your home are essential to design success...

Heating and Cooling Basics: Going with the Flow

In the natural pattern of air flow, cool air sinks, and hot air rises, so best practices must consider the primary role of your system. Based upon your geographic location, will heating or cooling needs prevail? As a general rule, ceiling mounted vents offer better cooling potential, while floor vents offer superior heat delivery. These principles should also be applied when locating return vents (the vents that pull air from the room to supply your HVAC system): For homes where heating is a primary concern, floor collection is advisable to pull from and warm the coldest air in the room, while higher wall collection vents better capture and condition warm air for more efficient air conditioning.

What Can Go Wrong When You Install AC Ducts Under the Floor?

  • Accessibility issues
    Locating ductwork in a crawlspace can make it extremely difficult to access for service (ie: addressing ductwork leaks, insulation issues, animal damage, et al.)
  • Furniture issues
    Arranging furniture to prevent blockages and allow for proper airflow often presents challenges with floor supply and/or return vents. Mid-floor locations are NOT recommended - though periphery locations may prove troublesome as well. (Think: sectional sofa, area rug, beds and dressers…)
  • Dirt
    Over time, dirt and debris tracked into your home can result in floor AC ducts that get exceedingly dirty very quickly, requiring more frequent duct cleaning.
  • Kids
    Children – especially young ones – present a wildcard, as they may inadvertently damage and block floor AC ducts and/or destroy air quality with an array of sabotages, stuffing everything into them from toys to tissues, dirt from potted plants, their evening milk... The possibilities are limitless.

Despite Drawbacks, Under-floor Installations Offer Significant Performance Over Attic Setups

Un-insulated attic installations typically suffer significant heat loss and HVAC performance issues, particularly in extreme climates that require heavy air conditioner use. In the case of extreme heat or cold, unconditioned attic space results in heat transfer - the loss of cold air in the summer, as well as heat loss in the winter - as conditioned air is lost to uninsulated attic space. In these situations, basement installation of ductwork or installation of ductwork inside the conditioned space of your home is ideal.

Energy Savings Offered by Moving Ducts Inside Living Space Is Significant

A case study by Energy Van Guard, an Energy Star partner whose mission is to increase the energy performance of homes, revealed substantial savings are offered by relocating ductwork, which outperform many other efficiency upgrades…

Ductwork issues leaving you all hot and bothered? You can count on the experts at Aire Serv® to get you out from under your problems. Contact us. We’ll help you solve your toughest cooling conundrums today.