For your air conditioner to work and serve you well, it has to be the right size in relation to your room or home where you install it. In air conditioners, sizing does not mean the AC unit’s actual physical size, but its British Thermal Units (BTU), which refers to its cooling capacity. This cooling capacity then must consider how big the room is, among many other factors. Otherwise, the wrong size would either be inadequate in cooling a space or too big that would leave everyone freezing. You might find it helpful to refer to this guide on how to size an air conditioner.
Factors to Consider in Sizing Air Conditioner
There are some factors you need to consider when sizing an air conditioner properly.
- Size of the room or space where the air conditioner will be installed. This is your foremost consideration, to have a sense of how strongly an air conditioner should spew and circulate its air to cool a room. You don’t want to make the mistake of having too small an air conditioner unit; otherwise, you would just end up wasting money.
- The number and type of windows in the space. The more windows you have, the larger the cooling capacity of your air conditioner needs to be. Since windows bring in light and heat to a room, this is what your air conditioning unit is up against. In contrast, fewer windows mean the cold air that your AC unit spreads gets to be contained better in the room. Window styles also help you determine how to size an air conditioner. If you have low-emissivity windows, you may opt for smaller air conditioner sizes since these types of windows are coated with a film that deflects the sun, so your home does not get too hot.
- The style of your house or space. So two rooms or spaces that have the same size in square meters do not mean they will require the same size of air conditioning unit. If you have a home with a high ceiling, that means your air conditioner has a lot of work to do, thus creating a bigger cooling capacity.
- The type of insulation in your house. The existing insulation in your house, especially in your ceiling, attic, and walls, are key in deciding what size air conditioner you should get. You may ask your air conditioner dealer to check your insulation type so you can have a more informed decision. If your house has inadequate insulation, you may need a larger air conditioner unit.
- The ductwork currently in your space. Your existing ductwork also determines what size you ought to purchase. Have this checked by an air conditioner technician to see its condition and replace a leaking one with a new installation.
- The number of residents in your house. The number of warm bodies you typically hold or accommodate in a living space will affect the area’s condition. The more people there are, the larger the air conditioner unit you need so that the cool air does not dissipate and is stronger than the heat generated by bodies.
- Where you are located. If you live in warmer regions, then you should opt for a bigger air conditioning system. How your house is positioned ought to be considered as well. If you live in a shady area canopied by trees, then a smaller air conditioner, all other factors considered, should suit you well.
Steps on How to Size an Air Conditioner
With these factors taken into account, here are your next steps and your best options so far on how to size an air conditioner.
- Take a measurement of your room where you will install an air conditioner. Calculate the size by multiplying the length and width of your space in square feet.
- Once you have the size in square feet, multiply this number by 25 BTU. This will result in your BTU per square foot for an approximation of the cooling capacity that you should go for, at the very least.
- If, for example, you plan to have one air conditioner for adjacent rooms that are divided by a wall but not a door, take the size of the entire area.
Then multiply this size by 25 BTU. Once you have the BTU per square foot, you either dial this cooling capacity measurement up or down depending on room conditions:
Is your room usually exposed to direct sunlight? Dial the cooling capacity up by 10 percent.
Or maybe your room is situated under a shade of trees? Then dial the capacity down by 10%.
Is it a kitchen you fit an air conditioner with? Since kitchens get very hot in the thick of all the cooking, it is advised to add 6,000 BTU to your calculated cooling capacity.
Are there usually more than two people in the room? Aside from these two, how many are they? Multiply this number of additional persons (excluding the first two persons) by 600 BTU; then add the resulting number to your original BTU per square foot. This is more or less the cooling capacity that you would need. Know more about measuring appliances.
Finally, you could use these rough estimates on how to size an air conditioner depending on your room’s size. A small bedroom may benefit from an air conditioner with a 5,000 to 6,500 cooling capacity. A medium-sized room accommodating more than two people, 7,000 to 8,500 BTU would be good. On the other hand, a large room, like a living room or family room, must go large with a cooling capacity of 9,800 to 12,500 BTU.