Put money back in your wallet with energy-efficient changes

By Bill Bullock

This is the first in a series of articles on energy use and practical information to help Memphis residents make wise decisions about ways to lower energy consumption and overall utility costs.

The factors that determine our monthly energy bill are the energy use of a particular appliance and the duration over which it is drawing energy. During the winter, the biggest contributor to our utility bills is heat. It draws a lot of energy when on, and in the peak winter months, it can be on a lot.

The major contributors to how often our thermostats call for heat are 1) our personal comfort requirements and habits, 2) the envelope of the house, 3) the type, age, and condition of the heating equipment and associated ducts, and 4) outside temperature and wind speed. We can have a significant influence on the first three.

Personal Habits

What is the most cost-effective thermostat setting? The answer is as close to off as you can stand it. Contrary to some “conventional” thought, it uses no more energy to warm up a cold house at the end of a workday than it would had you kept it warm the entire time. With the exception of a heat pump with electric emergency heat (which few reading this article have), it uses less energy to warm up that cold house. This is because, in Memphis, the laws of thermodynamics are strictly enforced.

And since many of us forget to set that thermostat back when we are away, a programmable thermostat can pay for itself if you program it to do the things you may forget to do. So if you can develop habits of setting the thermostat way down when you are away or asleep and wearing winter-appropriate clothing so you can keep the thermostat a little lower when you are awake, you will save energy. Consider a small electric space heater in a bathroom for infrequent use. Electric resistance heat is much more expensive than other forms of heat, but if you can get by with a lower temperature in the rest of the house, it can help reduce overall energy costs if used sparingly.

Building Envelope

This has to do with how tightly sealed and insulated your home is. You lose the most heat through your attic, so be sure to have lots of insulation there. Gaps around older loose-fitting doors and windows can let that cold air in as well. A lot of our midtown chimneys have no damper. In such a case, heat is being sucked from your home all winter. If you have plans to replace windows or doors, choose energy-efficient models and have them professionally installed. Wherever there are penetrations in outside walls (ie, gas pipes, electric lines, cable), seal those with insulating foam. Add insulating foam gaskets around switch and outlet covers, especially on outside walls. If you are considering a major renovation, be sure to insulate your walls. Specifications and considerations can be found on these improvements and more at www.mlgw.com and other energy sites.


If you heat with a natural gas-fired boiler and radiators, you can boast some of the most comfortable heat around. Unfortunately, unless your boiler is relatively new, you are probably sending more energy up the flue than you send into your home. Also, boilers are a bit slower to respond when trying to utilize thermostat setbacks for energy conservation.

If you have an old boiler but have had central air conditioning installed in your home, you may actually have a gas-fired furnace available within the existing blower unit. If so, consider having it piped for gas and properly vented, and use it in lieu of the boiler. Some older Memphis homes have floor furnaces. Keep those clean and have them inspected regularly—they are likely quite old.

If you have a ducted system, track down any leaks in your ducts in your attic and crawl space. Anytime you feel conditioned air getting out, sealing it with mastic compound is like putting money in the bank. After sealing, make sure ducts are wrapped with appropriate insulation.

Considering an equipment change? If you are upgrading or adding air conditioning, there is no better time to incorporate an efficient heating system into the design. Consider very high efficiency. A condensing furnace can eliminate the need to make expensive chimney upgrades because the exhaust gas can be vented with PVC pipe. A hybrid heat pump can also be a wise investment. It uses electricity during much of the winter to economically move heat from outside to in (an air conditioner in reverse), and when it’s really cold, an efficient gas furnace kicks in as auxiliary heat. Get several quotes and do your homework.

Log on to www.mlgw.com and click on “In Home Evaluation Program” to learn of MLGW/TVA incentives for making energy improvements and investments. Look at “Energy Tax Incentives” to see how some of these improvements qualify for Federal Tax Credits. Use “My Account” to track your energy use, get energy conservation tips, view and pay your bill, or sign up for paperless billing.

Bill Bullock has a degree in Mechanical Engineering, has been working in the energy field for over 25 years, and is a long-time resident of Midtown Memphis. If you have questions regarding this information, or energy use in general, contact him at bbullock@mlgw.org.


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