HVAC Efficiency: Vaulted Ceilings Pros and Cons
HVAC Efficiency: How Vaulted Ceilings Affect Your AC System
As a design feature, vaulted and high ceilings remain very appealing for home buyers. These relaxing features often add natural light and add space without adding square footage. If your dream home features vaulted or high ceilings, there are some HVAC Efficiency details you should be aware of that affect heating and air conditioning functions.
Stating the Obvious—Heat Rises
Air molecules that absorb heat energy move more and are lighter, while molecules that have lost their heat energy are heavier and sink. This is true on a global scale and inside every home. Healthy indoor air quality requires air circulation and hot air stubbornly tries to stay high, resisting movement. Vaulted ceilings often have a thinner insulation layer, which serves to keep the air heated.
Problems develop when hot air resists movement in high ceilings.
- That air becomes rather stale, and it doesn’t get cleaned often via the air filter.
- Painted or stained surfaces suffer when constantly exposed to hot, moist air.
- Stubborn hot air is helpful during the cooling season, keeping cool air down and hot air up. However, it is hard to overcome during the heating season because the furnace must work hard to heat higher spaces before the living area is heated.
- The HVAC system works harder in both the heating and cooling seasons, trying to move that hot air. This places undue strain on the blower motor.
Sizing. The HVAC system in each home is customized for each home with a formula called a load calculation. A technician collects information, including square footage, insulation level, number of windows, and doors. High ceilings are a factor in determining the proper size of your system and the technician will add load for each foot of added space in each room. Little can be done with an existing HVAC system but make sure that the load calculation for your next replacement takes high ceilings into the calculation.
Circulation. Moving stubborn hot air is essential and can be accomplished by several means.
- Using ceiling fans properly can move efficiently during both the cooling and heating seasons, but it requires a little information. Ceiling fans can turn in both a clockwise and counterclockwise rotation and the direction affects air movement. The counterclockwise rotation pushes air down and should be used during the cooling season. This mixes the air and allows the air conditioner to remove humidity while cooling the air. The clockwise rotation pulls air up during the heating season, pushing warm air out and down for comfort and mixing. Ceiling fans installed in vaulted ceilings usually have remote controls with rotation control.
- When a heating or cooling cycle begins, supply air is pushed into space via vents, usually located on the floor. At the same time, air returns to the central cabinet via plenums found high on the wall on each story. Adding a plenum in or near a vaulted ceiling can adequately move the stubborn air resisting normal airflow.
- It is generally best to leave the air conditioner fan in the hot, humid summer. Moving air is easy to keep moving, compared to trying to move stationary air.
Mini-split ductless solutions. Mini-split systems do not use ducts to move air but circulate air with small, room-sized air handlers. With this approach, the vaulted area can be zoned separately, and an air handler unit installed. This ensures that the air is being cooled and cleaned regularly.
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Schedule your free HVAC Efficiency consultation by calling AllCool AC & Heating at 281-238-9292 or contact us via email and let our NATE-certified HVAC technicians put their experience to work for you.