South Carolina Change Location
South Carolina » Save Energy & Money » Energy Savings Q&A » Get Powerful Home Advice

Get Powerful Home Advice

Duke Energy wants to help you understand energy usage and how to achieve greater comfort and energy savings in your homes. Get answers to your most asked questions.

Show / Hide All

What is the recommended temperature setting for air conditioning when a group cannot agree?

Unfortunately, there is no one ideal temperature setting. Every individual who has ever spent time with more than three or four people in the same air conditioned space has learned that everyone else seems to have a different definition of comfort. For most people wearing one layer of casual clothing, the ideal comfort temperature at any given time is in a very narrow range of maybe only two to three degrees. Not only do people have a narrow range of comfort, but this range often shifts up and down by a change in activities, clothing, health at that moment, season of the year and of course, age.

If you are cold in an air conditioned room, make sure you are not sitting in the direct flow of the air. This can cause an otherwise acceptable temperature to be uncomfortable. If this happens at work and you cannot move, use deflectors on the register to divert the air to an unused space or to the person who likes it cold.

There is no newspaper article or other argument that will resolve this issue and no one will “just get used to it” without changing activity level, clothing, or some other influencing factor. The best we can do is compromise on the temperature and ask some to wear more clothes and others to wear less. No one person or temperature is right or wrong. Find the midpoint temperature where the two sides are equally dissatisfied, and then dress accordingly.

Why is my upstairs so much hotter than the downstairs in the summer?

Cooling the upstairs of a two-story home is a challenge for many reasons:

  • The downstairs is usually closer to the air conditioner fan and it gets most of the airflow.
  • The thermostat, which is usually downstairs, senses the plentiful cool air in the downstairs, and shuts off the air conditioner before the upstairs is cool.
  • The upstairs has a hot attic above it. The ducts to the upstairs are commonly undersized considering the extra distance from the fan.

In addition, a two-story foyer or entrance hall can gather heat from any adjacent downstairs ceiling and allow it to rise to the upstairs. Homes with an upstairs “loft” and floor plans that are open to the upper level allow all the heat in the lower rooms to flow to the upstairs. In these situations, the downstairs has only a fraction of the air conditioning load compared to the upstairs.

Although common to many two story homes, a hot upstairs is not necessarily a law of nature. Unfortunately, it is easier to solve the problem during the initial design and construction of the home. You can install two air conditioners (and heating systems) and two thermostats, one upstairs and one down. Another solution is to install a zoned airflow system that constantly varies the airflow to different zones in the home according to the need at that time. The most practical and lowest cost solution for two-story homes is to use larger ducts to compensate for the extra distance and/or numerous turns in the routes to the upstairs.

In an existing home, closing registers on the first floor is a common practice. This may help cool the upper level rooms by forcing more air upstairs and at the same time reducing airflow to the downstairs, which needs less cooling. However, a hot upstairs is often the result of a poorly installed duct system, ductwork that is too small and/or a duct system that has too many restrictive turns. In these situations, closing off the good airflow in the downstairs may decrease the total system airflow to a point that the inside air conditioner coil freezes up.

Ask a heating contractor whether your ductwork is properly sized. A good design technician can make changes to get more air to your upstairs if the ductwork is accessible. Another option is to try a ceiling fan to counter the upward heat flow in rooms that are two stories high and open to the upstairs. Running the air conditioner fan all the time may also help.

How do you get rid of a musty smell in a damp basement?

Make sure the basement does not have water leaking through the foundation, plumbing leaks, roof leaks or other problems that involve liquid water. Since liquid water problems are usually very obvious and resolved immediately, most long term moisture problems in basements are usually caused by water vapor from the outside air.

Warm summer air is full of moisture. Do not open basement windows to try to dry out the basement. As the warm air moves into the cool basement, the air becomes nearly saturated and condensation will appear on any cool surface including basement walls and air conditioning ducts. Over time, these damp areas cause the basement odors. Even if you have a dehumidifier running to dry the air, it may run continuously unless you close up the basement and stop the source of the moisture.

In addition to making sure all basement windows are closed, running a central air conditioner can remove much of the basement moisture. But even if you air condition, cool basements and crawl spaces often require more dehumidification than an air conditioner can provide. Using a dehumidifier in these locations during the summer often solves the moisture problem.

If you do not have air conditioning, a damp basement is another reason to buy an air conditioner. In fact, if you run a large capacity dehumidifier 24/7 in an open basement, you may already be spending a good portion of the cost of air conditioning but you are getting no comfort for this expense. In warm, humid weather, close up the home and condition the air.

What can I do to help seal drafty windows?

Air leaking through old or poorly built windows is a considerable waste of energy. In very leaky homes, cold air infiltration can be responsible for up to 40 percent of the heating bills. New replacement windows can solve the problem, but if you are not ready to make that kind of an investment, there are much easier and less expensive remedies.

Adding caulking, weather-stripping, storm windows and purchasing new windows are all good things to do to help prevent drafts. You also can prevent air leaking through windows by covering them with plastic. This low-priced product is usually called a “window kit” and is sold at most home improvement centers. Follow the directions in the kit. You use a blow dryer to shrink the plastic to your window opening and the double-sided tape that is usually included in the kit holds the plastic around the window frame. Try to cover the entire window frame opening.

As long as you have an alternative door to use, you should also consider using this material on leaky sliding glass doors. It is amazing how much air can leak through these oversized windows, and it is usually in the very room in which the family gathers on a cold winter evening. Cold drafts not only cause the furnace to run more, but may also make you so uncomfortable that you raise the thermostat temperature to stay warm! Installing the plastic is inexpensive, and it stops a tremendous amount of air leakage.

We installed a new energy efficient furnace with a built-in humidifier and new windows, but now we have excessive moisture on the windows. What is the problem?

The new windows are probably not your problem. If you have good windows and you still have condensation, you have too much humidity inside your home. Having the proper amount of moisture is a challenge in the winter but it is the key to your comfort, the life of your home and maybe even your health.

If your old furnace was inside the home, it used your inside air to burn fuel and then it exhausted the air and most of your home’s moisture out the flue. Homes with these systems can be very dry. The new high-efficiency gas furnaces do not vent your inside air like the old systems. Your new furnace will save on energy usage and help the dry air problem, but now you may need to pay more attention to indoor moisture sources.

Your humidifier should be set to a lower humidity during cold weather and it should be adjusted frequently through the varying winter weather. Watch your windows. They will tell you if you are adding too much water.

Some homes do not use a humidifier and still have window condensation. To reduce this problem, use the bath vent fans when bathing and for 15 to 30 minutes after you are done. If you have a crawl space, make sure you have a layer of plastic over the dirt floor. If you live in a new home, your humidity may be from the building materials getting wet during construction. It may take a full winter season to dry them. If you have a basement, you may need to run a dehumidifier year-round. Have a few more fires in the fireplace. If this does not help, you may have an unusual or hidden moisture source that should be investigated by a home energy expert or a foundation specialist. Do not wait to solve a moisture problem.

What is an add-on heat pump system?

An add-on heat pump is an energy efficient heating system that is added to your furnace. A heat pump can be added to most any new or existing forced air furnace system. For example, if you heat with natural gas, your existing furnace combined with a new heat pump will give your home a dual fuel heating system that will save you hundreds of dollars per year. Consider these options when you want to invest in a more efficient heating and cooling system.

Suppose that you have a 2,000 square foot home, an 80 percent efficient natural gas furnace that is working properly and you spend $1,000 per winter to heat your home. Upgrading to a new 90 percent furnace will save you about $100 per year.

If nothing is wrong with your current furnace, you do have other options. For example, if your air conditioner has recently failed or needs major service or is just too old to trust, consider buying a heat pump. A heat pump is an air conditioner in the summer and a money-saving heating system in the winter. Your new dual fuel system will use both electricity and natural gas to heat the home, each running in the winter periods where they are most efficient. Using the $1,000 heating cost example, you could save about $300 in heating costs each winter. You could also save another $200 each summer when you air condition your home, since the new heat pump is so much more efficient than your old air conditioner.

You now save $500 per year by spending a bit more than the price of a new air conditioner. Your new heat pump will run in all the winter periods that are 30 degrees or higher. It is during this time that your heating costs will be cut in half. In the colder temperatures your gas furnace operates as it always has.

Why does my new home have ducts in the attic? Will this affect my heating costs?

Older homes often have the heating system and the ductwork in a basement or crawl space. Many new homes are built on a slab foundation, and the attic is a common place for the duct system. The ducts (supply and/or return air) often originate at a central box and spread across the attic space in every direction to reach all the rooms. A good portion of the heating and cooling energy can be lost in this case, resulting in higher bills.

Heating system air temperature can be anywhere from 100 to 140 degrees. Attic space, which is normally vented to the outside, can reach a chilling zero degrees on a cold winter night. As you attempt to heat your home, a portion of the heat is lost to the cold attic. Even if the ducts are made from a one-inch insulation material, they can still lose from 10 percent to 40 percent of heating energy and the same percent of heating capacity. Noninsulated, metal ducts are much worse.

In the summer air conditioning months, the same problem exists in reverse. You will be trying to send 55 degree air through a 120 degree attic space. Cover exposed attic ducts with six additional inches of insulation to reduce the energy loss. If the ductwork reaches high into the attic framing, it will be much more difficult to insulate. In this case, hire an insulation contractor to wrap these ducts with six inches of insulation.

How much money can you save by replacing old-style holiday lights with newer mini- or LED lights?

Let’s compare the cost of operating the various styles of lights to see which is the most economical. Old holiday lights range from 4 to 10 watts per bulb. Let’s assume you have the smaller size bulbs at an average of 6 watts each and you use 100 bulbs. This adds up to 600 watts. If you have them on for five hours each night for a month, at $.085 per kilowatt hour (kWh), you will spend about $7.65 per month for each set of 100 lights.

Common, inexpensive mini lights will only use about .4 watts per bulb. If it takes 300 lights to do the job of 100 old lights, then 300 bulbs at .4 watts each will add up to 120 watts. If they are on for five hours per night, at the same cost per kWh, this will cost about $1.53 per month.

Newer Light Emitting Diode (LED) lights are more expensive than the common mini lights, but they use even less energy and last much longer. At only .08 watts per light, 300 lights would add up to only 24 watts. If these lights are on for the same time as above, at $.085 per kWh, LED lights would cost you only $0.31 per month.

You may think that holiday traditions are worth a little extra money, but consider these facts: 500 old fashioned lights at 6 watts each, 10 flood bulbs at 100 watts each, four shining angels, Rudolph’s 100 watt nose and one glowing partridge in a pear tree, could easily add up to 5,000 watts. You will be so proud of this display you may want to light it 12 hours per night for 50 nights. Total estimated cost at $.085 per kWh: $255. Just for comparison, $255 would light over 10,000 LED (.08 watts) lights, all night…for every night of the year.