The diagram shows a house that air leaks into and out of it.
The house has three stories.First one is basement that has two rooms. In one room thereis air flow through vent and window. But in another room there is not.
Second one is ground floor that has three rooms, involving kitchen, bathroom and livingroom. In kitchen, heat loses through chase, light and fan vent. In contrast, air leaks into through window, door and chimney. Although bathroom has no windows, air leaks into by electrical outlet.
The last story is top floorthat air leaks out of the house at the highest extent by vents and lights.
In conclusion, to prevent from losing heat in a building, utilizing is important. The highest heat extent goes out through top floor and roof. On the other hand, air leaks into through vent and window. In this regard, providing proper equipment affects on the amount of losing heat. In result, wasting energy decreases.