If you're dreading facing another long hot summer with substandard and inefficient cooling methods for your home, now is the perfect time to look into buying a central air conditioning system. Thanks to federal tax credits for energy-efficient air conditioners and many local utility company rebates as well, it's never been more affordable to chuck those window units, floor fans, and evaporative coolers once and for all. Here are some basic tips on how to buy central air conditioning.

--Choose a quality contractor: The best contractors don't just sell you an appliance; they are valuable resources for selecting the right one for your home and getting it at an affordable price that will fit your budget. Most of us haven't a clue how to install an air conditioner ourselves, so make sure you really trust the company you go with and that they are licensed and insured.

--Capacity: Air conditioners are definitely not one-size-fits-all. Too large an appliance for your square footage will result in the system cycling on and off way too often, wasting energy. If the air conditioner is too small, it will not be able to cool all areas of your home effectively.

--Efficiency: Air conditioners fall into low, medium, and high-efficiency categories. Efficiency is measured by a SEER (Seasonal Energy Efficiency Rating). The SEER number for an appliance will fall between 10 and 23, with the higher number being the most efficient. Government standards demand that all air conditioners sold in the United States rate at least a 14; those that are rated 16 and higher qualify for Energy Star efficiency status. Your contractor will be able to recommend the appliance with the best SEER number that will both suit your needs as well as your budget.

--Price: Most heating and air contractors keep their pricing within the same general range; however, some of the more experienced contractors may have special long-standing relationships with manufacturers and be able to offer reduced prices on the products themselves. Make sure you get a bid from several contractors in order to make comparisons regarding labor costs, since these tend to vary greatly from contractor to contractor.

The best time to buy an air conditioner is during the spring or fall months since technicians tend to be less busy during these times and will be able to give you prompter service. Like any machine, your new air conditioner will require ongoing maintenance in order to operate at peak condition; many contractors offer cost-effective maintenance service agreements that help prevent little problems from getting bigger and costing a bundle.