So you’re thinking about having your air conditioner replaced. Maybe it’s noisy and expensive. Maybe it doesn’t keep the house comfortable anymore. Or maybe it’s just getting old. After all, 10 years is the maximum lifespan of central Air Conditioner these days.
You might be pleasantly surprised to find out that technology has made switching more attractive. For one thing, the newer efficient air conditioning systems are considerably more efficient. You’ll probably end up spending less on electricity this summer.
Second, because of this increased efficiency, you might be able to get by with a smaller unit.
Size does matter
When it comes to your Air Conditioner, bigger isn’t always better. The first step, before you even decide on the brand and choose some of those fancy options– like fan-only mode, or two-stage operation– is to have your house sized.
In HVAC talk, ‘sizing’ refers to an assessment of the space you want to keep cool and dry. Your contractor will conduct something called a Manual J
A Manual J takes into account many factors, like how many stories there are in your home, the number and size of doors and windows, how much insulation you have, and, of course, the climate in your region.
Do your homework
But before you hire an HVAC Contractor, it pays to have a little background on the subject.
Air conditioners cooling capacity is measured in BTUs (British Thermal Units). You will often see AC units described as ‘3-ton’ or ‘2.5-ton’. Each ‘ton’ is worth 12,000 BTUs. So if you buy a 2-ton unit, it will have a 24,000-BTU capacity.
As a very rough gauge,about 25 BTUs are needed to cool each square foot of space. So if your home is 2,000 square feet, you’d need about 50,000 BTUs, or a 4-ton unit.
However, that’s just the beginning. Then your contractor will factor in all of those other things– plus others like exposure, occupancy, insulation, and the number of rooms.