# Generated heat

Most of the people choose to install an air conditioner in their houses to provide them the comfort they need during summer. But before doing that, one should know the accurate dimensions of the air conditioner they need. If one achieves a smaller unit than necessary, it won’t take effect.

**Steps:**

- Establish which rooms of the house you want to cool with the air conditioner and measure their length and width. Do not take into account the height because it is not important. To find out the area of each room, multiply its width and length. The total area of the house results from adding together the areas of the room. Multiply the total area by 337 BTUs.
- The width and the height of your south oriented windows are also important. Find out the total area and multiply it by 871 BTUs. Also calculate the total area of your north oriented windows and multiply it by 166 BTUs.
- The number of people living in the rooms to be cooled is also important, because humans also produce heat. Multiply it by 400 BTUs.
- Also take into account every light source in the house. Multiply the number of watts per light source by 4.25 BTUs.
- If there are any electrical appliances or machines in the house, multiply the maximum wattage they consume by 3.15 BTUs.
- Add up all the BTUs amounts that you have calculated and buy an air conditioner unit that is able to remove all the resulting heat generated in your house.