If you're thinking about installing a new gas furnace, the Trane Home Comfort Institute says it's also a good time to think about adding accessories that can improve the comfort levels in your home even more. These include an electronic air cleaner, a humidifier and a programmable thermostat.

Electronic air cleaners remove the dirt, dust, grease, pollen spores and other airborne particles in your home that can cause unnecessary physical discomfort and damage furnishings.

Electronic air cleaners are usually installed in the duct carrying air back to the furnace and remove up to 95% of the undesirable airborne particles. A disposable furnace filter only removes 10% to 15% of the contaminants.

Humidifiers help maintain a healthy humidity level throughout your house during the winter when a heating system can dry out the air.

The normal humidity range for human comfort is between 35% and 45% relative humidity. As air becomes drier, throats, eyes and noses can become irritated. Static electricity also becomes a problem. A properly sized and installed humidifier can correct these conditions.

Programmable thermostats raise or lower the temperature automatically, thereby saving energy while maintaining the standard of comfort you desire.

With these easy-to-use "smart" thermostats, you simply pick the temperature settings you want, and the thermostat takes over the job of keeping you comfortable. Programmable thermostats can change the temperature of a home up to four times a day.

In terms of energy savings, Trane Home Comfort Institute experts say you'll save about 3% of your heating costs for every degree you lower your thermostat during winter.

They also say that if you don't already have central air conditioning, replacing your furnace is a good time to think about this addition as well. Be sure to tell your heating contractor of your desire so that he can match the needs of the new cooling system with that of the new gas furnace.