Archive for the ‘Cooling’ Category

Whether it is central air-conditioning or room units, they can quickly cool a broiling bedroom, a sticky family room, or other hot spots in your house, you can find instant relief for a reasonable price. Individual units put the cooling where you want it when you need it if the climate in your area does not warrant whole-house air-conditioning or if you do not want to spend the money to have central air installed. Current models are also up to 30 percent more efficient than those of a decade ago and now they may carry up to 5-year warranties.

Matching the air conditioner to the room you want to cool should be your first consideration. If the unit is too small, it simply will not cool the space. If it is too large, it will cool the space so quickly that the thermostat will shut the unit down before it can lower the humidity level in the space. The result is a cool room that feels damp and clammy.

Room air conditioners are “sized” according to their cooling capacity. This is expressed in BTUH (British Thermal Unit of Heating) per hour. You will find the rating on the packaging or in the literature, or ask your installer. Typically, it ranges from 5,000 BTUH to 25,000 BTUH.

Here is a simple chart to help you understand the correlation between the size of the space to be cooled with the BTUH of the unit:

Area to be cooled
in square feet



5,000 – 6,000


6,000 – 8,500

400 – 550

8,500 – 11,000

550 – 875

11,000 – 15,000

875 – 1,200

15,000 – 19,000

There are many other ways to more precisely size your space. If there is any information you would specifically like to know, simply send us a note and we can provide the answer for you as well.

Whichever way you determine the size you need, remember that for the 115V circuits typical of bedrooms and living rooms, you will have to stay below 15,000 BTUH of cooling. Units above 15,000 will require a 230V circuit. In addition, if you want to cool a large, open L- or T-shaped area, you are better off with two smaller units versus one large one. Two units will prevent cold spots in front of the unit and warm spots around the corner.

Energy efficiency is the next shopping consideration. Refereed to as Energy Efficiency Ration (EER), this figure is the cooling capacity divided by the electrical power required to run the unit. The higher the number, the better. Most 115V have an EER of 9-10. Any unit above 10 is considered extremely efficient. It should be a minimum of at least 10.

While you are in the store, or while your installer is setting it up in your home, practice! Practice removing the filter for cleaning. See if the controls are placed conveniently for you. Will the unit be installed through the wall so that it is at shoulder or head level? If it is a through-the-wall unit, are the controls on the bottom or side? If it has a remote control, do you know how to use it? Is it placed far enough away from the thermostat? If you are installing it yourself, is there an electrical plug within close proximity? Did you read the instructions? Did you check to see if the unit will fit in the location you have selected? Are there any modifications to the space that must be made before the unit is installed, and did you make them FIRST?

I realize these questions might seem foolish, but it is important to know the answers and be prepared before you start. Installers, such as us, are always able to assist you, but installing your own system is easy if you follow the directions.

We get a tremendous amount of calls about charging room air-conditioners. We suggest this – if the unit is over three years old, buy a new one. With the prices of room units these days, we consider them expendable items. You CAN bring a unit to an installer, and they can recharge them, but if the unit requires Freon 12 for any reason, it simply is not cost effective to have it done by an installer.

We hope these hints have helped you with your decisions on room air-conditioning units. If you have any questions, or comments, please let us know at this site or by writing to me, Pat Fields.

Good luck and see you soon with more hints and tips you can use to save you money!

Find us on Facebook