2. Do your research: Consult manufacturer Web sites and product evaluation sources. Consult sources like the Good Housekeeping Institute that help guide consumers in making informed purchasing decisions on a variety of products, including heating and cooling equipment. These resources evaluate products on performance, costs, and long-term reliability, as well as compare product features among brands in different categories.

3. Find a dealer that you are comfortable with. Most cities have hundreds of places from which you can purchase an air conditioner, heat pump or furnace. Research several dealers in your area and get references from previous customers. Make sure that the dealer is NATE (North American Technician Excellence Inc.) certified. NATE is the leading certification program for technicians in the heating, ventilation, air-conditioning and refrigeration (HVAC/R) industry and is the only program supported by the entire industry. Not only is trust a key consideration during the purchase and installation process, but service after the sale is extremely important as well. The company you make a major purchase from is as important as the quality of the equipment itself.

4. Ask to have the air inside your home tested before buying. Lennox introduced a simple and cost-effective indoor air quality testing service called the Lennox Healthy Advantage Program. The service, which is available through select Lennox dealers, is designed to help homeowners identify potential air-quality issues and specific solutions for improving overall home comfort. As part of the service, an air-quality monitor is placed inside the home to measure the most common indoor air quality factors ¯ temperature, humidity, carbon monoxide, carbon dioxide, odors, chemical vapors and airborne particles – and a report is generated by an independent testing lab. Based on the results of the test, homeowners can then make informed purchase decisions about the type of heating, cooling and indoor air quality equipment they need to improve their home's overall comfort level.

5. Look for design features, ask questions and discuss needs. Today's heating and cooling systems feature a variety of bells and whistles that can increase comfort and convenience levels, but some are essential for optimum performance. For example, expect your air conditioners to have an adjustable thermostat with at least two cooling speeds and two fan speeds. The unit also should feature an energy efficiency setting, which stops the fan when the unit is not cooling, therefore conserving electricity. In addition, consider the overall product design. The Dave Lennox Signature® Collection includes furnaces, heat pumps and air conditioners that are equipped with special design features to reduce noise pollution and help conserve energy.

6. Check the energy efficiency rating. Consumers should check their furnace's annual fuel utilization efficiency (AFUE) and their air conditioner's seasonal efficiency rating (SEER). The most energy-efficient furnaces have an AFUE of 90 percent or higher. For central air conditioners, the national minimum energy-efficiency rating requires a 13 SEER rating. And in order to achieve maximum energy efficiency, you may even wish to consider models that have a SEER of 15 or higher. Lennox Industries offers the Dave Lennox Signature® Collection XC21 air conditioner, the most energy-efficient and quiet air conditioner on the market, with a SEER rating up to 20.5.

7. Factor noise into the equation. Older heating and cooling units tend to be noisy. An important consideration that homeowners tend to overlook is that today you can find units that are designed to help decrease noise while providing total comfort. Product lines such as the Dave Lennox Signature® Collection and Elite® Series air conditioners, furnaces and heat pumps, quietly deliver a superior level of comfort by using exclusive SilentComfort™ technology.

8. Save money and conserve energy with ENERGY STAR®-rated products. Visit www.energystar.gov for a list of products that have the ENERGY STAR® rating, which means that the equipment has above average AFUE and SEER ratings and uses about 50 percent less energy than standard equipment. These factors equate to significant long-term savings and environmental benefits for a homeowner.

9. Look for a warranty. Make sure your new furnace or air conditioner has at least a one-year warranty that covers not only parts on the entire system but also the labor if something should go wrong. For an extra cost, some retailers will offer an extended warranty plan that covers the equipment for four to five years, and dealers often offer annual maintenance agreements that cover routine system maintenance.

10. Don't put a price tag on comfort. Purchase a furnace or air conditioner that is priced within your budget, but don't compromise your comfort level, household energy efficiency or long-term savings by purchasing a system that will not satisfy your needs and wants well into the future. Gather research and make a list of the features you're looking for in a system, and stick to the list. You will be happier with your investment down the road.