Debunking Energy Myths

Summer is a great time to weatherize your home with improvements that will benefit you in both cold and hot weather. Many of the improvements will reduce your energy bills and most will improve the comfort of your home or apartment.

The Ohio Department of Development's Office of Energy Efficiency (OEE) shares a few commonly held myths about hot summer weather, energy efficiency and weatherizing homes in Ohio.

Myth Number 1: Using ceiling fans will reduce your air conditioning costs.

Most ceiling fan motors are very inefficient, converting 80 to 95 percent of the electricity used by the motor into heat. The blade design on most ceiling fans is also inefficient because flat blades are poor at converting the rotational energy into downward airflow. Inefficient motors and blades result in only 1 to 2 percent of the electricity that enters the motor being converted to downward airflow. The vast majority of ceiling fans includes lights, which are usually inefficient incandescent or halogen bulbs. The heat generated from the lights not only represents wasted energy use but also contradicts the design objective of ceiling fans, which is to cool the user.

Myth Number 2: All homes built today are energy efficient.

Although most Ohio homes are built to meet Model Energy Code (MEC), they are not as energy efficient as they could be. You can be assured you are buying an energy efficient home if you buy an Energy Star® home. Energy Star® homes are certified to be at least 30 percent more efficient than a comparable home built to meet MEC.

Myth Number 3: It is better to buy an air conditioning system larger than you really need.

The energy and comfort problems caused by an oversized air conditioning system are greater than those caused by an oversized furnace. Whole house air conditioners actually work in two ways. First, they cool the air. Second, they dehumidify (remove moisture from) the air. If an air conditioner is oversized, it will have the capacity to quickly cool the air. This will satisfy the thermostat and the system will shut down before moisture can be removed. This will result in cool, clammy air. To remove the moisture, you would have to lower the thermostat and unnecessarily increase your energy usage (and energy bill).

Myth Number 4: Powered attic fans will reduce your air conditioning costs.

Under ideal circumstances, attic fans would increase the air exchange in your attic, reducing the attic temperature. Reduced attic temperature means less heat transfer from your attic to your living spaces. This would reduce your cooling costs. However, in most homes, attic fans do not work this way because unsealed air leakage paths connect the attic and living spaces. When the attic fan exhausts attic air, conditioned air is actually drawn from the home and out the attic. This loss of conditioned air will increase your air conditioning costs. To add to the problem, as air is drawn from the house, warm and humid air from outside is drawn into the living spaces. Your air conditioner will now have to work harder to cool the air and remove the moisture.

Myth Number 5: Replacing windows and doors are a great way to reduce energy bills.

As a general rule, it is not cost-effective to replace working windows and doors. Ultimately, it comes down to the cost to install the measures versus the resulting energy savings. Windows and doors are expensive and have paybacks usually measured in decades. There are other improvements, including adding insulation, sealing air leakages, sealing duct leakages and replacing inefficient mechanical systems that may be more effective at reducing energy use. These measures can have paybacks of less than five years.

Myth Number 6: It always costs more to build an energy efficient home.

If energy improvements are added to an existing design, it may cost more to build an energy efficient home. If you approach the design with energy efficiency in mind, a systems approach will result in increased efficiency at no additional cost. The U.S. Department of Energy Building America program has proven this approach to be superior on many levels, including improved durability, safety, comfort and energy efficiency. By designing a better building shell, you can downsize the heating and cooling equipment. The increased shell costs will be offset by decreased costs for the mechanical systems. Lower monthly fuel bills will also offset any slightly increased mortgage cost resulting in lower total monthly bills.

Myth Number 7: Changing your thermostat setting costs more than leaving it at one setting.

Set your thermostat to the warmest setting comfortable. You can set it 5 to 10 degrees higher when you are not at home for an extended period of time. This will reduce your cooling bills.

Myth #8: Older window air conditioners are energy efficient.

Window air conditioners have been manufactured to be much more energy efficient than they used to be. If you have an old air conditioner, you are probably wasting a lot of energy each month, and unnecessarily increasing your energy bills. Consider shopping for a new one. Look for an Energy Star® labeled window air conditioner to be assured it is energy efficient.

Myth Number 9: Buying a used window air conditioner is a great bargain.

You may be able to pay very little for a used window air conditioner, but those savings will be quickly erased by its large monthly energy use. Buying a new Energy Star® window air conditioner will save you so much on your electric bill that it is a better bargain than a used one.

Myth Number 10: All new appliances and mechanical equipment are energy efficient.

The energy efficiency of new appliances, mechanical equipment and consumer electronics varies. The easiest and most effective way to determine if a new produce is energy efficient is to look for the Energy Star® logo or label. Energy Star® is a national, voluntary labeling program created and managed by the U.S. Environmental Protection Agency and U.S. Department of Energy. The program promotes energy-efficient products and helps reduce pollution associated with energy generation. Go to the Energy Star® website or call 888-STAR-YES for more information about qualifying products and where they can be purchased in your area.

Myth Number 11: A house can be made too airtight

Houses cannot be too tight, but they can be under-ventilated. A better approach is to install controlled ventilation. During hot weather, a leaky house will have a difficult time controlling humidity, which will cause comfort problems and increased energy use.

Myth Number 12: Solar energy does not work in Ohio.

The sun does shine in Ohio. Photovoltaics (PV) can generate electricity at your home and offset the need to purchase electricity from your electricity provider. To provide hot water, solar water heating is a viable option to consider.

Myth Number 13: Compact Fluorescent Lights (CFLs) take a long time to light.

CFLs, especially if exposed to cooler temperatures, can take 60 seconds or longer to reach full output. With the newer electronic ballast, the slow start and flicker of some CFLs have been eliminated. However, CFLs may not be right for every application.

Myth Number 14: CFLs aren't as bright as incandescent bulbs.

CFLs produce more light per watt of energy consumed than incandescent bulbs. That's why they are described as energy efficient. When it comes to replacing an incandescent bulb with a CFL, light output is a key factor to compare. Choose by lumens, not by watts.

Myth Number 15: The light from CFLs makes colors look "funny."

CFL packages show information about a bulb's ability to show the true colors of an object. The "Color Rendering Index" (CRI) is a scale of 0 to 100. The higher the CRI, the more natural the colors will look. A CRI Between 70 and 80 is acceptable for most home applications.

Myth Number 16: CFLs emit a cold, bluish light.

The actual color appearance of the light is called the color temperature and is measured in Kelvin (K).

Temperature Appearance

  • 3000 K reddish-yellow, warm
  • 4000 K whiter, cool white
  • 5000 K bluish, cold

Warmer lights (and thus cooler color temperatures) are better for most home uses.

Myth Number 17: They don't make CFLs in the type of bulb that I need.

The bulb selection seems to get better daily. More sizes and different shapes are available at grocery stores, home improvement stores, and lighting retailers. CFLs can be found to fit in chandeliers, above bathroom mirrors, in wall sconces, and table lamps. Some CFLs now on the market can be installed in circuits with dimmers or timers. Three-way CFLs are even available. Manufacturers offer a range of products that vary by color rendering index and temperature. Read the packaging label to find the CFL that is right for your use.

Myth Number 18: CFLs cost too much.

CFLs cost much less to own and operate than incandescent bulbs. They use only 1/3 to 1/4 the energy of incandescent bulbs to produce the same light (lumens). CFLs can last from 5 to 10 times longer than incandescent bulbs. Result: fewer bulb changes. With a much longer lifetime and more light produced per kwh, Energy Star® CFLs cost less to own and operate than incandescent bulbs.

Light Bulb Specs
Light bulb projected lifespan
50,000 hours
10,000 hours
1,200 hours
Watts per bulb (equivalent 60 watts)
Cost per bulb
KWh of electricity used over 50,000 hours
Cost of electricity (at $0.10 per KWh)
Bulbs needed for 50,000 hours of use
Equivalent 50,000 hours bulb expense
Total cost for 50,000 hours

Energy Savings over 50,000 hours, assuming 25 bulbs per household:

Light Bulb Specs
Total cost for 25 bulbs
Savings to household by switching from incandescent


  • Cost of electricity will vary. The figures used above are for comparison only, and are not exact.
  • Estimates of bulb lifespan are projected. Some manufacturers claim the new LED bulbs will last up to 25 years under normal household use, but this is not proven.
  • Bulb breakage and bulb replacement costs have not been factored into this comparison chart. Incandescent bulbs and CFL bulbs are more easily broken than LEDs, which increases their cost of use.

Myth Number 19: Watts measure the amount of light produced.

Watts measure the energy used; lumens measure the amount of light produced. Some activities, like reading and sewing, require more lumens than more general uses. When you buy CFLs, select those that produce the amount of light (lumens) for the task. That way you pay only for what you need.