Choose High Efficiency - High efficiency HVAC equipment can reduce utility bills by 10 - 30% over minimum efficiency equipment. For a typical household this can mean hundreds of dollars savings per year. These energy cost savings can represent a 20 to 40 percent return on investment after taxes for the extra cost of high efficiency equipment! And the energy savings go on. High efficiency HVAC equipment can improve home comfort several ways with more even heating and cooling and quieter operation. The quality construction, improved technology, and attention to detail found in high efficiency HVAC products usually results in longer equipment life and often longer warranties on key components.

The Compressor - The compressor is the motor or pump that makes an air conditioner work and can be very expensive to replace. Air conditioners usually have either a scroll or reciprocating compressor. Scroll compressors are more efficient and make less noise and are therefore more expensive initially. Reciprocating compressors are less efficient, make more noise and usually come with a shorter warranty life. Most compressors have a five year parts warranty and many come with a ten year warranty standard. Some units offer an additional warranty which can be purchased separately.

Variable Speed Air Handlers - Most systems are standard, meaning the motor runs at only one speed and is either running on or off. Anytime the blower is running, it is at full capacity using the maximum amount of energy. The motor of a variable speed air handler is smarter than the average blower, it automatically varies its speed based on your homes heating and cooling requirements. Other benefits include quieter, better control of humidity, cleaner air and more even temperatures.

Match the System - If you have to change the outdoor air conditioning or condensing unit consider changing the indoor coil to match it. Ask your contractor if the indoor or evaporator coil is compatible or if it also needs to be changed. Mismatching a high efficient condensing unit with a low efficient indoor coil can not only cost you most if not all of the added efficiency but can also damage your compressor valves and cause your compressor to wear out much sooner than it normally would.Consider the Noise level - Another important factor to consider when buying a unit is its noise level. If your unit has a low sound level, you will hardly notice it is operating, while high levels may mean many sleepless nights and annoyed neighbors. Air conditioning and heating equipment is rated by a sound rating number or SRN, which is based on American Refrigeration Institute tests and range from 6.8 which is the quietest to 13 which is the loudest. Most air conditioners operate at from 7 to 9 bels. It doesn't sound like much but a unit operating at 9 bels is actually 10 times louder than a unit operating at 8 bels.

Don't Forget the Ductwork - While you are replacing your system consider having your ductwork checked to see if it needs any repairs or if it needs to be replaced. If some rooms in your home are too hot or too cold, if the insulation on your ductwork is peeling or if there is a buildup of contaminants inside, consider having your ducts evaluated to see if they need replacing. Also, return air grills in each room should be evaluated to see if they are properly sized and working correctly.

Consider a Programmable Thermostat - Programmable thermostats can be set to adjust the temperature setting according to a user's schedule. These thermostats typically have a digital interface that allows more precise temperature control and a wider range of options or features, and can automatically store and repeat settings daily with allowance for manual override. By eliminating manual setback, which is easy to forget, they allow the setting of more comfortable temperatures in the morning before occupants wake. Temperature setback can be adjusted for both heating and cooling seasons.

Consider Your Comfort - There are other add-ons to your system that you might consider to increase your comfort level and help your system to keep you healthier. Air cleaners are great for those with allergies and will help keep your house cleaner. These range from simple electrostatic filters to more expensive electronic air cleaners and ultraviolet filters. Humidifiers can help with dry skin, sore throats, breathing problems, cracking wood, and help with static electricity. Humidistat's are like traditional thermostats, but also monitor and control humidity. Zoning Systems divide your home into several separate zones or areas with similar comfort needs, with separate thermostats and dampers that automatically adjust the temperature in each of those zones. This allows you to cool only the area where you need it, so you save money. Also you can allow different people in the same home to adjust the comfort level to suit themselves.

Consider your Unique Needs - Since everybody's home is unique you will want to enlist the help of a reputable contractor to sort through the options. A good contactor will be able to help you balance your budget considerations, utilities available, your need for comfort, logistical consideration, climate in your area, and other factors.