Air conditioning technology is changing all the time, and so are sizes. They’re getting small, more efficient, and a better value for consumers. At the same time, getting something that’s too small won’t help you. Here’s how to calculate the right size for any home.

Split Systems Vs Packaged Units

There are two main choices when it comes to A/C units: split systems and packaged units. Split systems consist of an outdoor metal cabinet that holds the condenser and compressor and an indoor evaporator system. In a split system, the indoor cabinet may also contain the furnace or heat pump.

With a packaged unit, the exap, condenser, and compressor are all in one cabinet, which is usually mounted on the roof or on a concrete slab next to the home. This type of A/C system is more common with commercial buildings than residential ones.

But, if you’re having a reputable company, like Pioneer Comfort Systems, install your new A/C, ask about both to see which one will save you the most amount of money over the long-term.

Sizing Up Your Needs

It’s impossible to give a “rule of thumb” for these systems as they all vary by the make and model of the unit, the efficiency of your home, and the contractor’s installation.

But, proper diagnosis and measurements will nearly guarantee that you get the right size for your home. Your contractor should show up to your house with proper diagnostic equipment like a Manual J or Manual D, which is software that analyzes how much conditioning capacity you need. It will also analyze the ductwork for you.

Based on these measurements, the contractor can recommend the right air conditioning unit. If he doesn’t do these measurements, be wary of any recommendation he gives you.

A Word On Hiring Contractors

A good contractor can make the difference between a shoddy install and a unit that works flawlessly between regular service intervals. Contractors are not all created equally. Some have more or better skills than others.

Some have been in the business longer. This experience factor is often what makes a huge difference in both the price you pay and the quality of service you get. While an experienced contractor may charge more per hour, they also work faster compared to an unskilled or underskilled contractor, and the final outcome is better.

For example, an unskilled contractor may give you a great deal on an install, but you’ll more than make up for it in servicing if the contractor doesn’t install everything properly. You might actually pay less in the long-run with an experienced contractor, even though you will be charged more upfront.

Contractors should be licensed, bonded, and insured.

They should also own diagnostic equipment and keep their employees trained on all of the latest high-efficiency HVAC units on the market. They should be certified by a trade organization like North American Technician Excellence (NATE) or the Sheet Metal Air Conditioning Contractors’ National Association or the Air Conditioning Contractors of America.

Try to get referrals from friends before doing business with anyone. And, when in doubt, check Internet forums like Angie’s List.

William A. Milligan works as a building contractor. He enjoys sharing his industry insights on the web. His posts appear mainly on home renovation and DIY blog sites.