Air conditioner ideas for home and office that can help you know which brands to think about for your home and office the best way. Air conditioner sizing means finding the air conditioner that can balance the heat gains and losses within a building. When selecting a portable air conditioner it is very important to select a unit with the proper cooling capacity for your requirements. Oversized units will not perform at maximum efficiency and will probable not give you as many years of use due to erratic operation. Air conditioners that can be made to move from one place to another on casters are called Portable Air Conditioners.