Efficient digital thermostat; courtesy US Department of Energy
This article was updated on 12/27/20.
Conventional HVAC systems contribute an efficient amount of comfort to our busy lives, thanks to technology, but unless they are configured properly, they can use some of that efficiency. Which of course, compromises energy bills.
Typically, middle class homes are fitted out with a single thermostat and a system of ductwork that moves heated or cooled air to the individual rooms. These components are installed by the general contractor. There's a reason what the homeowner gets is called "contractor-grade."
This is generally fine in smaller or single-story residences; a relatively happy compromise. HVAC design engineers develop systems so that your thermostat is physically situated where it senses air flow.
It is popular to locate it where the air makes its way back to the return air filter for yet another cycle. The height is important. It should be placed in a comfort zone approximately five feet above floor level, although this may vary a bit depending on code.
As you will recall from your high school physics class, warm air rises and cooler air sinks. Once you begin to add in ceiling fans, cathedral ceilings, and upstairs bedrooms, it is not hard to see how a compromise develops and your comfort may be sacrificed.
You Might Lower Energy Costs with a HVAC Zone System
One common solution that will save money and keep family members more comfortable is by converting your single thermostat to a zone controlled system. The initial step, as with all projects, is careful planning.
Start by taking a long look at your homes floor plan and then divide your rooms up into logical zones. If you are lucky enough to have a copy of your blueprints (and you should insist on it, if you are the first owner), so much the better. If not, simply sketch it yourself or get a copy from your local building department.
As an example, you might label your kitchen and living room might be designated zone 1 (heavily used), the bedrooms zone 2 (mostly used at night), your basement zone 3, and the dining room/den/ zone 4.
Obviously, all homes as well as family dynamics are unique, but this will get you started and pointed in the right direction. If you feel uncomfortable making these decisions yourself, consider consulting with your best local HVAC contractor. You will need one anyhow. Be careful selecting one. Here are some tips on selecting a Contractor.
Implementation of your zone is now rather straightforward; you will simply add a programmable thermostat to each zone, and motorized dampers to the ducts that supply the zones. Your contractor can do all that for you.
You might find that your ductwork may need to be replaced or modified to some extent, but you will recoup your expenses in short order. The US Department of Energy reports that you can save around 10% a year on your heating and cooling bills. And you may qualify for a federal energy tax credit. What's not to love as energy rates tend to ramp up?
The Dual Heating and Air Conditioner Solution
Another optional solution, specifically in 2-story homes is to use 2 separate heating and cooling systems, one dedicated to your first floor and the second one to your second floor, where the bedrooms generally are.
This can also be a good solution in the right circumstances, but it does involve having two HVAC systems with all the maintenance and expense that entails. Then again, everything is a trade-off to some extent; the overall wear-and-tear will be distributed.
A further consideration is that it can still present a challenge to balance individual rooms. An obvious advantage is that if your sleeping quarters are upstairs, that dedicated unit can be economized during the day and the downstairs unit may be economized at night. Win-win.
As a final possibility, if all is well except for one limited zone, especially with a 1-story home, a more efficient approach might be to simply install a ductless mini-split air conditioner system in that zone. In any event, heater and air conditioner zone control technology is certainly worth a look.
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About the author:
Kelly R. Smith was a commercial carpenter for 20 years before returning to night school at the University of Houston where he earned a Bachelors Degree in Computer Science. After working at NASA for a few years, he went on to develop software for the transportation and financial and energy trading industries. He has been writing, in one capacity or another, since he could hold a pencil. As a freelance writer now, he specializes in producing articles and blog content for a variety of clients. His personal blog is at I Can Fix Up My Home Blog where he muses on many different topics.