When should you consider buying an energy-efficient air conditioner? Now is a good time. There are two very good reasons why this is so. First, the efficient unit will save you considerable money over time, compared to your aging AC. Also, considering our depleted fuel reserves and the stress on our environment, energy savings are important for everyone. While it will cost upfront to make the purchase, the savings over the life of the unit will more than justify the expense.
You should do your research, apply the formulas for energy efficiency, learn to recognize the terms, and read the big yellow stickers on appliances. An air conditioner is a major purchase, and you want to be an informed shopper. Most likely you will not be installing the unit yourself, so you will be well advised to shop for an air conditioning company as well. A local specialist will know the conditions in your area. They will be able to understand that SEER rating, and explain it to you as well. That highly-qualified professional will be able to evaluate your home space, and determine the right Btu rating as well.