Modern HVAC systems add an incredible amount of comfort to our fast-paced lives, but in most cases they are far less energy efficient, comfortable, or affordable as they could be. The typical middle class home has one thermostat and a network of ducts that delivers temperature-conditioned air to the individual rooms.
In many cases the result is a relatively happy compromise. The HVAC engineer designs the system so that the thermostat is located where it can sense air flow, generally as it makes its way back to the return air filter. Height-wise, the thermostat is situated in a “comfort zone” about 5 feet off the floor.
A short review of your high school physics textbook will prompt you to recall that warm air rises, cooler air sinks. Add to the mix ceiling fans, cathedral ceilings, and upstairs bedrooms, and you can see how the compromise evolves and individual comfort may be sacrificed.
Lower Utility Bills with a HVAC Zone System
A smart solution that can both save money and keep family members happy is by converting to a zone controlled system. The first step is the planning one. Look at the home's floor plan and divide the rooms up into logical “zones”.
For example, the kitchen and living room might be designated zone 1, the bedrooms zone 2, the basement home theater zone 3, and the dining room/den/ zone 4. Of course all homes and family dynamics are different, but this gives you an idea.
The implementation of the zone concept is now to just add a thermostat to each zone, and motorized dampers to the ducts that supply the zones. In many cases the duct work system may need to be replaced or modified.
The Dual Heating and Air Conditioner Solution
Another common solution, especially in 2-story homes is to have 2 separate HVAC systems, one dedicated to the first floor and one dedicated to the second. This is a good solution, but it still involves having two central air conditioner units with all the maintenance and expense that entails.
Another drawback is that it can still be a challenge to balance individual rooms. An advantage is that if the bedrooms are upstairs, that unit can be economized during the day and the downstairs unit may be economized at night.
Finally, if all is well except for one limited zone, especially in a 1-story residence, a more effective approach might be to simply install a ductless mini-split air conditioner system.
Kelly Smith - Kelly has over 30 years experience as a journeyman carpenter and 20 as a freelance writer and photographer.
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