Q: When I called someone out to have my 17-year-old air conditioner fixed, the repair person said it was beyond repair and quoted me a price to have it replaced. This is a pretty well-known company, but I do not like to be rushed into making a decision, especially one that involves thousands of dollars.

A: It's always a good idea to get another opinion: pick up the phone on the spot and call another heating and air company, describe the problem you're having and tell them the make, model, efficiency ratings and size of the new unit the repair person is trying to sell you, and see what they say. There's a chance it could be fixed, though it's a safe bet that you'll save money by replacing any unit 15 years or older with a new efficient unit. But you need more information and options to make a wise decision.

Q: What about brand names? Are some brands really better than others or are we just paying extra for a name?

A: There are several good brands on the market. Most heating and air contractors deal with one or two lines, but can service all major brands. In fact, many name brands are manufactured by the same company. There are more important factors than brand names to consider when comparing systems.

These include the following:

1. Compare the Seasonal Energy Efficiency Rating (SEER) -- a number from 10 to 16. (Warning: anything rated under 10 SEERS is below current standards and not acceptable in new construction). Some companies are still pushing 9 and 10 SEER units in the remodel market at bargain-basement prices because they're already obsolete.) The higher the SEER value, the more expensive the investment, the longer the warranties and the lower the utility and repair bills. The lower the SEER, the lower the initial cost, the shorter the warranties and the lower the utility company rebate. They are also much more costly to run.
2. Consider how long you plan to live in the house. If you intend to move in a year or two, a high efficiency unit may not be needed. But if you expect to live there three years or longer, it's good to know how soon you can expect to recapture the extra $1,000 or so you spend when you buy the higher efficiency unit, and see real savings in ever -- rising utility costs and repairs from then on.
3. Compare the warranties available on the units you are considering. The better a unit is, the longer the manufacturer is willing to warrant the parts and labor. Some offer a 10 year parts and labor from the manufacturer, which means if anything at all goes wrong during the next 10 years, the manufacturers will pay us (or another heating and air contractor) to repair it. For a nominal fee, it's even transferable to a new homeowner. Some contractors may offer what seems like a similar warranty in-house, but beware. Since this kind of warranty is with this contractor only, if this company goes out of business the warranty goes right out the window.
4. Check out the contractor you choose to install the unit. Is he or she willing to sit down and spend some time with you to explain all your options and answer your questions? Is he or she properly licensed and insured? How long has this company been doing remodels? Many contractors switched to remodeling from new construction when the new housing market declined, but there's a lot of difference.

Remodeling specialists are more attuned to accommodating homeowners' special needs. For example, some can design systems which let the homeowner move the outside unit away from the pool, enclose it in a closet or enable them to shut down registers in an extra bedroom without the adverse affects this would cause on a system designed for a new home. What kind of references does this company have? Take the time to check them out. Are their former customers happy with the job they did and their responsiveness and service afterwards? Would they recommend them to friends or hire them again?

Q: Why is the price difference between an 11 SEER and a 12 SEER system so much less than the difference between a 12 SEER and a 13 SEER unit?

A: It takes a different technique, extra parts and more time and expertise to hook up a 13 or greater SEER unit than an 11 or 12 SEER. But if you plan to live in a house three or more years, it's smart to spend a little more now than you may have intended to safeguard against some problems that may come up later, to escalating energy costs, to repair bills.

Q: Why is one quote for a new system higher than another one I received?

A: If bids on comparable systems vary, there are details to consider: Is the other company planning to use the old air return register, while another suggests a new one will work better? Are they modifying the duct work, as some propose? Are they replacing your registers? Are they replacing the 17-year-old copper tubing between your inside and outside units? Manufacturers may decline to honor their 10-year warranties on new equipment if the old tubing was not replaced.

Just take the time to do your homework and don't let anyone rush you into making such a costly decision.

by Kathy Maynard, reprinted courtesy of HomeAdvisor.com