HVAC: What kind of longevity can you expect?

Depending on locale, the costs for heating and cooling your home can take up a significant portion of your household operating budget. The experts at Energy Star estimate that as much as half of the energy a typical home uses may be devoted to maintaining a comfortable interior temperature.

When shopping for HVAC components, it only makes sense that outstanding energy efficiency might be the most desired characteristic. However, you may also want to consider the equipment's expected longevity. After all, purchasing many HVAC components can be a major investment.

New HVAC components: How long should they last?

There are many variables that come into play when estimating how long a particular HVAC component might function. One of the biggest issues you have little control over: your local climate. An air conditioning compressor in south Florida or Arizona is probably going to get much more use than the same unit installed in Maine or Wisconsin. Just the opposite might be true for a gas fireplace or electric heat pump.

Proper sizing is also important -- an undersized furnace may have to work overtime to keep a home warm. Along the same line, a house that's poorly insulated can cause that furnace to have to work much harder to maintain a comfortable temperature.

And don't forget about maintenance -- whether you're purchasing an entire HVAC system or just a ceiling fan, keeping it clean and serviced on a regular basis can extend the unit's functional life. Lastly, the quality of the equipment can also affect its longevity. HVAC components are one commodity where you often do get what you pay for - both in durability and energy efficiency.

But setting all of the variables aside, how long can you expect various HVAC components to last? According to studies done by the National Association of Home Builders and the International Association of Certified Home Inspectors, most HVAC equipment should last a decade or longer with average use. Here are some of their longevity estimates for various components most likely to be used in your home:

• Central air conditioners -- Typically, a central air conditioning system should last from 10 to 15 years with regular maintenance.
• Dehumidifiers -- If you're using a dehumidifier to remove moisture from your basement, expect it to operate for about eight years before it's time to shop for a new unit.
• Ducting -- The NAHB estimates that the ductwork in your home should last about 10 years. A report done by InterNACHI might be more accurate on this HVAC component: their study indicates that ducts should function properly for 60 to 100 years.
• Heat pumps -- If you have an electric heat pump heating system, plan on replacing the exterior unit after about 16 years.
• Thermostats -- Expect your home's thermostat(s) to last about 35 years.
• Electric radiant heaters -- The most common of this type of room conditioner might be baseboard heaters. The NAHB and InterNACHI both project that these convenient room conditioners should function for approximately 40 years.
• Hot water or steam radiant heater -- If you live in an older home with hot water or steam radiators in many of the rooms, the components of the system are rated for at least 15 years.
• Diffusers, grilles, and registers -- Almost every type of residential heating and cooling system utilizes these devices to dispense conditioned air. Both the NAHB and InterNACHI estimate they should last about 40 years.
• Dampers -- These are small flaps used to regulate air flow located in the main trunk lines of many HVAC systems. While most are mechanical or operated by hand, advanced layouts may have electronic dampers. Expect your dampers to last 20 or more years.
• Attic fans -- If you utilize a fan to remove hot air from your attic, it should operate as designed for about 15 to 25 years according to the NACHI.
• Ceiling fans -- These are attractive and great for circulating air throughout a room. The InterNACHI report indicates that your ceiling fans should perform as designed for 5 to 10 years.
• Gas fireplace -- While many families consider gas fireplaces to be a cosmetic accessory, numerous models can heat one or more rooms in a home. You should get about 15 years of use out of your unit.
• Condenser -- If you have the most common type of central air conditioning, this is the outdoor unit. The InterNACHI projects that your condenser should last from 8 to 20 years.

While both the NAHB and the InterNACHI put extensive research into their longevity reports, keep in mind that the data is based on average use and only an estimate. The functional life of your HVAC components could deviate from their projections.

HVAC equipment costs

As you can imagine, with such a variety of HVAC equipment available there is a wide price range among the components. Items such as diffusers and ceiling fans are offered in many different sizes and finishes that can affect their costs. A standard 4-by-14-inch, brown metal, louvered floor register is offered at Lowes for about $9. However, if you want designer styling and a brass or nickel finish, expect to pay about $19 for the same size.

There's even more of a price variance for ceiling fans. A basic budget-friendly, 52-inch model can be purchased at Lowes for about $40, but they also offer more stylish ceiling fans with similar functions that approach $800. There are numerous models available between the two extremes -- you can normally find very nice fans for around $150 to $250.

Gas fireplaces are priced according to size, heat output, and the options and finishes available on a manufacturer's models. Heatilator offers their best-selling Novus gas fireplace in sizes between 30 and 42 inches at prices that start about $1,250. If you want their top of the line Heirloom model that has a masonry appearance and sizes up to 50 inches, pricing begins at $4,150.

Major HVAC components such as furnaces and central air conditioning systems have their pricing determined by output and energy efficiency. When purchasing this type of equipment, it's almost always a good idea to have load calculations performed on your home by a trained HVAC technician. This can help to ensure you're getting the tonnage that best suits the home and your family's lifestyle.

Central air conditioners are rated according to their seasonal energy efficiency ratio and capacity. SEER is a measurement of the amount of energy the unit uses to reach a particular amount of cooling. Expect air conditioners with high SEER ratings to cost more than their average counterparts, but the higher price can often be recouped with the potential operational savings.

HVAC component pros and cons

So what are the various pros and cons of different types of HVAC components? Perhaps the biggest consideration when choosing an entire system to heat and cool your home is the availability and pricing of fuel in your area. In many regions natural gas or propane is less expensive than electricity, so a gas furnace might be a good choice.

However, if the reverse is true, you may want to think about a heat pump configuration for winter heat. One thing to keep in mind though: heat pump systems don't function as well in regions that get extremely cold.

An estimator at Griffith Energy Services, Inc believes that central air conditioning systems with SEER ratings above 20 might not always be a good investment. These units feature two compressors and both must be replaced if one goes bad -- a repair that can be expensive. In his opinion, a properly sized 15 SEER unit might be a better choice.

Lastly, while a gas fireplace can provide ambiance and heat for several rooms, they can also be a fire hazard if not installed with proper clearance. Always follow manufacturers' recommendations when placing a unit in your home or better yet, get a professional installation.