It’s funny and it’s true. Most people do not concern themselves overmuch with the price of a new air conditioner— until after it’s installed. Then they start to wonder whether they got a good deal, or if the contractor took advantage of them, or whether they could have gotten away with a smaller unit.

We should be clear that we’re talking about homeowners who plan to stay where they are until the kids are grown or until they downsize. Folks who just bought a new house, or baby boomers whose AC finally bit the dust . . . those kinds of situations.

For the milleniums who plan to rent forever, or for people who are moving every two years because of some job situation: This probably does not apply.

First, check out heat pumps

That said, our first comment should be, Look into a heat pump. These gadgets use the natural geothermal temperature of the Earth to heat AND COOL your home. You only pay for the electricity to operate the pump. The initial cost is high– $4,500-6,000–  but your outlay depends on the design of the geothermal collection. According to DOE, the payoff should come within five to 10 years. Plus the system will last 25 years (for inside components) and 50 years for the ground loop. So you can add this as an asset when you eventually sell the house.

How about a conventional AC system? It depends on whether there is already ductwork in the house. Just the AC unit added to existing ductwork should cost $3,500-4,000 for a 2,000-square-foot home. But that figure should be treated as a starting point. If the ductwork needs reworking— which it may, due to sizing differences or the age of the ducts— the price goes up. For a home that has no ducts, you might pay twice that amount ($7,000-8000).

For a discussion about how a system should be sized, how to find a good contractor, energy efficiency and much more, check out our service pages: http://www.acdoctor.com/get-educated/.

Just as a rough guide, here’s how the leading brands rank in terms of price: Amana, American Standard, Bryant, Lennox, and Trane are all in roughly the same range. Rheem’s economy model is about $1,000 less. American Standard and Bryant offer the highest-price, off-the-shelf models of these brands.

If you get a few estimates from contractors, it will help sort out some of the issues involved with your particular situation. Here’s our site, which allows you to enter your zip code and find a good contractor in your area: http://www.acdoctor.com/find-contractor/

And before you make the decision, here’s a thumbnail presentation of popular brands and their features and price levels: http://www.acdoctor.com/Air-Conditioners-p-1-c-61.html. And remember a word from the wise: Don’t make a buying decision based on saving a couple hundred bucks. If you buy an energy-efficient system, you may save that every year for the rest of your days. Now stay cool.