Portable Air Conditioners and BTUs - What You Need to Know

Why portable air conditioners?

For areas where installing a traditional air conditioning unit is impractical, impossible, or cost-prohibitive, a portable air conditioner can help you stay cool and comfortable. Some of the greatest advantages of a portable air conditioner is its maneuverability and simple installation. Although portable air conditioners still need to be vented, they're portable in the sense that permanent installation isn't required, and most units have caster wheels which allow you to move the air conditioner from room to room. Portable air conditioners are also a cost-effective alternative to central air conditioning systems because they allow you to cool specific areas instead of an entire home.

How do they work?

In terms of design considerations, portable air conditioners are relatively simple appliances. A box-like configuration holds both the cold and hot sides of the air conditioner in one and an exhaust hose expels heat. Water is condensed out of the air, and most portable air conditioners collect this water in an internal drain bucket or through a drain hose. As well, some models use evaporative technology and produce very little to no water at all.

Many portable air conditioners available on the market are also multi-functional in that they offer more than just portable cooling. In fact, some portable air conditioners include built-in dehumidifiers, air purifiers, and even heaters - making them truly versatile and not just suitable for the summer heat.

Portable AC BTU ratings

However, many consumers often overlook certain factors when purchasing a portable air conditioner, and one of the most common mistakes is not paying attention to a portable AC's BTU rating. BTU stands for British Thermal Unit, and it is a unit of energy used in the power, steam generation, and heating and air conditioning industries. Essentially, an air conditioner's BTU describes its power and cooling capacity and the higher the BTU value, the stronger the air conditioner.

Portable air conditioner cooling capacities usually range from 5,000 BTUs to as high as 30,000 BTUs, and the size you need will depend on the area being cooled. If you choose a portable air conditioner with the wrong BTU value, your cooling efficiency can be affected. So if an air conditioner has a higher BTU rating than the corresponding room size, the unit will cycle off too quickly, and the air conditioner will not properly remove the humidity from the air. On the other hand, if a portable air conditioner has a lower BTU rating than the required room size, the unit will not adequately cool the room.

Follow the steps below to calculate your room's square footage and find out the BTUs you need to properly cool your area from the preceding chart:

1. Measure your room dimensions by multiplying length by width.
2. Verify the size of your window opening.
3. Check the plug type and electrical requirements of your room.
4. Find the recommended BTU measurements from the chart below.

For example, if your room measures 18 feet by 25 feet, your calculations would look like this:

18' x 25' = 450 square feet
450 square feet = portable air conditioner with 10,000 BTUs

Alternatively, to get a quick ballpark figure of the BTUs you will need for your room, multiply the square footage of the room by 35 to get a very rough estimate.

Please note that the figures in the chart above are estimates based on average room conditions in a moderate climate; therefore, pay attention to the following exceptions if they apply to your room or home:

• For sunny areas or second story and higher homes, add BTUs by 10%
• For shaded areas, reduce the BTUs by 10%
• For each additional person over two persons in a room, add 600 BTUs
• For kitchen cooling, add 4,000 BTUs

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