Air Conditioner Systems

This Blog was posted by Smithson Valley Services Air Conditioning. We serve the Texas Hill Country, including Blanco | Bulverde | Canyon Lake | Fisher | Kendalia | New Braunfels | North San Antonio | Sattler | Sisterdale | Smithson Valley | Spring Branch | Startzville

Air Conditioners

Beat The Summer Heat – What Size A/C Should You Buy

What size air conditioner do I need?

A larger air conditioner will not always provide more cooling. It should be sized for the room area. It should operate long enough to remove moisture from the air if properly sized. The moisture removed from the room produces the feeling of cooling. Unfortunately, many people rush to purchase a window air conditioner by buying too large a model.

Too large a unit can provide less cooling than a smaller, appropriately sized unit. This is because its run time is too short with an oversized air conditioner. Consequently, it does not remove enough moisture from the room to produce a feeling of comfort. If you’re A/C seems to cycle off and then back on every few minutes and does a poor job of cooling, it is probably oversized for the room. More on this webpage
Air conditioners are rated in BTUs. British Thermal Units measure how much heat is transferred from the room being cooled to where the heat is dumped out of doors. This is why the cooling coil inside the room is cool to the touch while the part that hangs outside is boiling.

A window air conditioner in the average household room can be as low as 4000 BTU. While 5000, 6000, and 8000 are the most common sizes purchased.

How do I determine what size A/C I need?
Following is a basic sizing chart for calculating the window air conditioner needed for a room. Calculate the room’s size by multiplying the room’s width by the length of the room. Use your room size to determine what BTUs are required to cool that particular room size.

room in sq ft——–room in sq m———-A/C size in BTU’s


Based on a room occupied by two adults, having average insulation, several windows, and sun exposure.

Which is the best room for the placement of an air conditioner?

Wherever it gives the most comfort is where it should be installed. We usually suggest the bedroom if you only have one air conditioner. This is because most people find that if they can sleep comfortably during a hot summer night, their next day’s work will be much easier. Getting through a hot day at work becomes easier when you know you will sleep comfortably that night.

Some people do not like a cool sleeping environment, so they tend to place it in a living or family room. Or some people will place it in the family room because the whole family can sleep there. Get out the sleeping bags and turn them into an adventure for the young. Beats waking up in the morning to find a dog, cat, and four kids in the bed with you.

Also, window air conditioners can be noisy, which may disturb sleep. Others find the fan drone promotes sleep because all the neighborhood noises are drowned out. Some people say the air conditioner works as well as a sleeping pill.

But whichever room you eventually pick, don’t expect the impossible from you’re A/C. It is not meant to cool more than one room or open area. Air conditioners will not cool other rooms. This is because a window air conditioner blower is not very powerful. It is sized to cool one open area, not several interconnected rooms. Therefore, a couple of smaller units may be better for your home than one large unit.

Lastly, remember to secure the air conditioner in the window properly. Once installed, a piece of wood to stop the window from being lifted is a good idea. If you have wooden sills, simply adding a wood screw at the top of the raised window (the one you had to raise to install the A/C) will only take a minute. Otherwise, an intruder could gain access to the house by lifting the window and letting the A/C fallout. This could result in the loss of both your valuables and the air conditioner.