Are you looking for a new air conditioner for your home? Will you select a portable or window unit to cool one room, or are you looking at central air conditioning to cool your entire home?
It’s not as easy as heading down to your big box store and selecting the first cooling system you find. A lot of variables go into making your final selection: your room size, the heat load of the room, and what type of system you already have in place. 
If you look at air conditioners, one of the first things you’ll notice is that air conditioning units are rated by BTUs. BTU stands for British Thermal Unit. It measures the amount of energy needed to raise one pound of water one degree at sea level.
As a general rule of thumb, an air conditioner should be sized at 20 BTUs per square feet of living space. Of course, there are exceptions to the rule.
- How much sun do certain rooms get?
- Is your house shaded or out in the open?
- How many floors does your home have?
- How many people occupy your home?
- Kitchens need more cooling capacity.
- How active is your home?
The higher the number of BTUs isn’t always a good thing. If the air conditioner is too big for the space, it can cause the environment to cool too quickly, then cycle off. To maintain the set temperature, it cycles on and off, wearing the equipment out before its time. It not only might become overheated, but it shortens the life cycle as well.
The opposite is equally damaging. If the unit isn’t large enough, it never reaches the desired temperature. Meaning the system will never cycle off. Eventually, the load is too much for your air conditioner to handle, and it will damage the equipment.
This is why it’s important to pay attention to room size and select the right air conditioner for your circumstances.
In the simplest of terms, here are a few recommendations:
150 square feet needs 5,000 BTUs
400 square feet needs 9,000 BTUs
700 square feet needs 14,000 BTUs
1000 square feet needs 18,000 BTUs
1400 square feet needs 23,000 BTUs
2700 square feet needs 36,000 BTUs
Working with a professional HVAC technician will ensure you select the right air conditioner for your cooling needs. With tougher federal regulations and more innovation than ever, the perfect air conditioner can fit whatever works best for your budget.