(the diagram illustrate how natural air circulates within a house and how heat loss occurs as a result.)
Overall, the most heat escapes through the upper areas of the house, particular in the roof, whereas air tends in enter the house from lower parts.
A considerable plenty of air leaks out the house from the roof area, mainly through plumbing stack vent, attic hatch and recessed lights. Besides, a significant portion of heat loss through kitchen and bathroom fan vent.
In contrast, air tends to enter the house from areas closer the ground. These include crawl space, outdoor faucet and dayer vent. Air can also leaks into and out through chases and other small openings around the lower parts of the building, increasing the need for heating and energy comsumption.
