OREANDA-NEWS. Heating. Ventilation. Air Conditioning. Collectively known as “HVAC,” this system can account for a significant portion of one's monthly electric bill.

As we move into the dog days of summer, Duke Energy, the nation's largest electric utility, is offering ways to increase the efficiency of HVAC systems during the remaining warm-weather months.

“The energy used to cool a home in the summer - and heat it during winter - can account for half of monthly electric bills,” said Duke Energy's Smart USD aver® product manager, Nathan Cranford.

“Properly maintaining a home's HVAC system can save money and also improve comfort in the home,” Cranford said.

To increase HVAC efficiency during summer months, Duke Energy recommends the following:

Air conditioner

A new, high-efficiency air conditioner uses about half the energy of older models. If an air conditioner is less than 10 years old, maintain it well and keep it. If an air conditioner is more than 10 years old, the best alternative might be to replace it with a new, high-efficiency model.

During summer months, set the thermostat at the highest comfortable setting. Energy Star recommends a minimum set point of 78 degrees Fahrenheit. Adjusting a thermostat up even a few degrees can yield significant savings on electric bills.

Clean or replace HVAC filters monthly at a minimum; more often, if needed.

Keep coils on the exterior AC unit free of dirt, grass clippings and leaves.

Humidity makes an AC unit work harder. While it's tempting to give your AC unit a rest on cooler nights and open the windows instead, it might be better to keep the windows closed to keep drier, cooler air indoors. Also, if hot weather is forecast for the next day, keep the AC on - and doors and windows closed through the night - to keep humidity out.

To maintain efficiency and peak performance, HVAC systems should be checked regularly by a qualified heating and air conditioning contractor.

Around the house

Use ceiling or oscillating fans to circulate air in rooms. Turn fans off when you leave a room; fans cool people, not rooms.

On hot, sunny days, close drapes, curtains and blinds. Blocking direct heat from the sun reduces demand on your AC unit.

Turn off unnecessary lights and use energy-efficient light bulbs that use less electricity and emit less heat.

Seal air leaks with caulking and weather stripping, and minimize door traffic to keep cool air inside.

In the attic

Repair leaky duct work. If room air vents are located in your home's ceiling, the duct system runs through the attic. Have a professional check to make sure cool air isn't escaping into the attic through leaky ducts. Properly sealed and insulated ducts can save up to 20 percent on the cost to cool a home.

Prevent cool air inside your home from escaping by adding sufficient attic insulation and sealing any ceiling cracks.

“Just as vehicles need regular tune-ups, HVAC systems also should be serviced on a regular basis,” Cranford said. “Implementing just some of these recommendations is a great start toward lowering your monthly electric bill, keeping your home cool and comfortable, and ensuring your HVAC system functions efficiently.”

Duke Energy offers its qualified customers rebates to help offset the cost of making many HVAC efficiency improvements.