What Type of Window Air Conditioner Can Be Installed in an Old House With Small Windows?

Window AC Unit

• While window units aren't manufactured as small as portable air conditioner units, there are some models small enough to fit into a little vertical sliding window. All that's required is a nearby power outlet and a window opening large enough to fit the unit. To best determine if a window unit is right for you, measure the open window and look for a unit that fits the dimensions.

  After the unit is installed in the windowsill, it needs to be secured to the outside wall with a mounting kit, which sometimes includes V-support brackets, which attach to the bottom of the unit and to the outside wall, supporting the weight at the back of the unit. Accordion panels pull out to close up the space between the window sides and the air conditioner. The open window slides down into the top guard rail of the unit to prevent the appliance from falling backwards. A window unit can even be installed in a horizontal sliding window with a bit of tweaking.

Portable AC Unit In a Sliding Window

• The easiest of all air conditioner installations is the portable unit installed into a sliding window of almost any size. A portable unit features an exhaust hose, which connects at the back of the unit and to the window slider component that comes supplied with the air conditioner. The window slider component can be stretched or narrowed to fit the diameter of the open vertical or horizontal sliding window. The component is installed parallel to the window sash, and the window is then shut on top of the component to pin it in place. While support brackets aren't required for a portable air conditioner window component, you can install L brackets on top of the open window to prevent it from being opened.

Portable AC Unit In a Casement Window

• Some portable air conditioner units come with a special casement window component, which is flat and slender so that it can fit as efficiently as possible between the two small casement windows. The two windows are secured with string or a rubber band around the two window latches. Weather seal can be inserted into the openings created by the installation to prevent cold air from escaping.

Evaporative Unit

• An evaporative air cooler doesn't function like an air conditioner, but it does create cold air using cold water and ice. Some units are portable and require no installation while other smaller units install directly into a small window.