Going green with your heating and AC isn't only good for the environment, it's also great for your wallet; approximately 40 percent of residential energy bills are for heating and cooling.

Over the past decade, technology has improved tot he point where the new highly efficient, environmentally friendly heating and cooling units available can pay for themselves in a very short amount of time in lower utility bills.

If your system is more than ten years old, or isn't heating and cooling as well as it did last year, it may be time to replace it with a new, energy efficient system. In addition to replacing your older, less efficient system, you can save energy and make your home more environmentally friendly by following a few simple tips.

Problem:
In the winter, warm air inside your home rises and escapes into the attic through holes and gaps. It's replaced by colder exterior air that's pulled in through cracks and gaps in the lower levels. That leads to drafty, uncomfortable rooms and high energy bills, even in newer homes.

Solutions:

Eliminate leaks
Use a combination of caulk, foam board, expandable sealant, and weather stripping to fill gaps. Attics in particular are often full of holes from recessed lights, electrical wiring, chimney chases, and more. Look for dirty insulation, which is a sign of air leaks. In the basement, check for gaps around ductwork and plumbing pipes. And don't forget about window and door frames, as well as electrical outlets and switches. Cracked caulking and staining around those openings are indications of air leaks.

Check insulation levels
If your attic has less than 11 inches of fiberglass or rock wool or 8 inches of cellulose, you would probably benefit by adding more. Also check for missing insulation, over the attic hatch, for example. Compressed insulation loses its effectiveness, so don't store things on top of it. You may also need to add insulation in the basement or crawl space.

Correct ductwork
It's the last step, and the one that's the most overlooked. Spending $500 to seal leaky or poorly insulated ducts that run through crawl spaces, attics, or other unconditioned areas can save you about $400 per year, according to the Energy Efficient Rehab Advisor, an online calculator available at http://rehabadvisor.pathnet.org Remediation is dirty work that requires the right materials. Leave it to a qualified heating and cooling contractor.

You should also have your heating and cooling equipment inspected annually, and change furnace and A/C filters monthly. A programmable thermostat is also worth every penny. By automatically lowering your heating-system thermostat 5 to 10 degrees at night and during the day if no one is home, the device will shave up to 20 percent off of your heating costs. You can also save on cooling costs by raising the thermostat five degrees and using ceiling fans.