Contrary to popular belief, a powerful air conditioner does not necessarily mean a better one for your needs. Air conditioners with a higher capacity are not only costlier, but they can also lead to higher energy bills every summer. In fact, a powerful air conditioner can make your house clammy instead of comfortably cool.

But an air conditioner that is too small for your needs can also come with its own set of disadvantages. It will have to work harder to cool your house and the energy bills will stay high. This is why it is important to have an air conditioner that is just the right size for the size of your home in Phoenix. Such a unit will provide the right degree of cooling while eliminating humidity and the monthly energy consumption will likely remain moderate.

Determining the Ideal Cooling Capacity

The cooling capacity of an air conditioner is measured in British Thermal Units or BTUs. Another term commonly used to specify air conditioner size is ‘tons’ where one ton equals 12,000 BTUs. Without going into the technical aspects of all this, it may be sufficient if you just know how to calculate the required capacity in relation to the area to be cooled. Basic math can get you there.

Calculate the area of the space by multiplying the length by the width. If the room has an irregular shape, some basic geometry can prove useful. After you calculate the square footage you need to cool, multiply it by 25 BTUs. The result you come up with is roughly the ideal BTU capacity you require.

This formula can give you an approximate idea of the capacity required, but there are quite a few other factors that will have to be considered before you make your purchase. These may include:

  • For a room that gets a lot of shade, you should lower the BTU capacity by 10% and for a space that sees a lot of sunshine, increase it by 10%. Remember to figure in the fact that deciduous trees grow leaves in summer and lose them in winter.
  • When looking for an air conditioner for a space that will be typically occupied by more than two people, you must add an extra 600 BTUs per individual. (For example, the family room.)
  • Add 4,000 BTU to your figure if the air conditioner is for a kitchen because it is a space that generates plenty of heat.

Some Things to Consider

You are likely to approach an HVAC expert when preparing to put in a new central AC. These professionals will probably use the scientifically accurate “Manual J” method to calculate the required size. While you should use professional assistance, it is not a bad idea to get familiarized with the process.

Besides the size of your home, there are a few other vital factors that will figure in this comprehensive “Manual J” process. These include:

  • The location of your house in relation to the sun.
  • The type of shade your home gets (as mentioned earlier), and the tree cover around the house.
  • The number of windows in your home, their size, and the directions they face.
  • Whether your walls and ducts are well insulated or if not, and whether you are planning on insulating them in the future.

You should also account for any home improvement plans you want to implement in the foreseeable future, such as extending the house, putting in a skylight or huge windows, or an extra wing. All these will change your air conditioning needs.

The Significance of Size

An Oversized AC

An air conditioner that is too big for your home will take you back in time to the 80’s. You will have an AC that turns on quickly, cools your house fast, and then turns off.  Your house will get cooled soon, but as the air conditioner is not functioning consistently, heat will seep into the home quickly and the unit will have to switch on again.

An AC That is Too Small

An air conditioner that is smaller than needed will still cool your house (unless it is far too small), but it will have to work too hard. The issue here is that cooling the entire house will take a longer time for a small air conditioner as it does not have enough power to complete the cooling as quickly as you would want. It may also break down quicker since it has to work so hard to maintain the temperature you have it set on.

That is not ideal! The little engine that could would become the little engine that tires out soon and collapses on you.

Key Takeaway

Accurately calculating the capacity of an air conditioner for your home is of critical importance before you proceed with the purchase and have it installed. The unit is a permanent fixture and changing it later is easier said than done!

If your air conditioner is on the verge of breaking down or you need a unit for your new premises, it is important to get the size right for your new ac unit purchase. An air conditioner of the correct size can be rewarding in terms of cooling comfort as well as energy savings all through the summer. And we know those Arizona summers in the Phoenix area and Tucson can be brutal.