Window AC / September 2, 2018 / Denise Brisette.
The answer is It depends on the wall thickness. Sleeve specifications for some window air conditioner manufacturers include the maximum wall thickness before it will cover part of the louvers. For example Amanas 18000 BTU models have a max of 8.5 inches. If the wall thickness is at or below that these models can be used in as a wall air conditioner without adversely affecting function. So whats the problem if the wall covers a little of the louvers? Two things: 1) restriction of air movement and therefore reduced efficiency and 2) these units pull air in very powerfully. Cut wall edges could become loose allowing material to be sucked into the unit and potentially causing damage.
This will help you determine the amount of BTU s necessary to cool your room adequately. For example an 8000 BTU unit will cool a room up to about 350 square feet. Another thing to consider when buying a window unit is any special features that come with the unit. In particular most window units include louvers that let you direct airflow programmable timers so that you can set the unit to turn off or on when you wish and energy efficient features like multiple fan speeds. Many units also come standard with a remote control so that you can adjust the temperature from across the room.
Side panels fill the gaps on the sides. These are also very thin so most of the sleeve is uncovered and outside. This allows for placement of ventilation louvers on the sides and top allowing free movement of air. This is the primary difference between the two types. The wide availability of louver space allows the unit to move a lot of air and this means window units can be quite powerful up to 3 tons or 36000 BTU. So window A/Cs can be effective for very large rooms. In contrast a wall air conditioner sleeve is designed for a hole through the wall. Walls vary substantially in thickness.
The most commonly used air conditioners are window air conditioners. This is due mostly to the fact that they are the cheapest alternative when it comes to cooling our homes. But there are other reasons also. For example they install in a window out of the way. Install it and forget it. These units are also available with electric heat options. Window air conditioners were once so noisy that they were nicknamed window bangers. This term was very accurate and well deserved. However todays window air conditioners are very different from the ones many of us learned to hate.