The diagram illustrates the main points where heat is lost and energy is wasted in a typical house. It highlights how air leaks both into and out of the building through various structural openings and ventilation systems.
Overall, the majority of heat escapes through the upper parts of the house, particularly the roof and attic area, while cooler air tends to enter through lower sections such as the basement and crawl space. Various vents, outlets and lighting fixtures also contribute to energy loss throughout the house.
In the upper section of the building, warm air primarily escapes through the attic hatch, recessed lighting fixtures and plumbing stack vents located on the roof. Bathroom ventilation systems further allow heated air to leave the house. Because warm air naturally rises, the roof and attic represent the most significant areas of heat loss.
Within the living spaces, several smaller openings also contribute to energy waste. Electrical outlets, windows and dryer vents allow air to leak out of the house. In the kitchen, recessed lights and the kitchen fan vent serve as additional pathways for escaping air. By contrast, cooler air tends to enter the house through the lower structure, particularly from the crawl space and other openings around the basement, reducing the overall energy efficiency of the home.