Stack effects
Stack effects increase building air infiltration and blow heat out of any structure. It also increases the overall rate of air infiltration driven by the stack effect. That is one reason why heat loss occur in residential homes,
The taller the building height between low and high leaks, the stronger will be the stack pressure. In a tall New York City building where top floor tenants kept the windows open in winter – they were too hot. The stack effect was a virtual gale of out-blowing hot air at the windows. If we used tissue and we taped it to the under-side of the window sash seeing it flap. Any desktop papers near an open window would simply blow outside from the heat sucking outward!
These same stack effects and thus building heat losses occur in one and two story residential homes as well.
Not only do stack effects draw heat out of a building. It includes any indoor air contaminants such as airborne crawl space mold are drawn upwards through the rest of the building.
Air and heat loss leaks in old building floors can be tricky to seal – particularly with board-type subflooring. If the building is built over a vented crawlspace or an unheated basement, the floor should be sealed. It should be sealed as well as possible from the prime living space.
This limits air infiltration and keeps moisture (and possibly airborne mold or radon gas if present) out of the living space. If the basement is finished and heated, it is usually sealed at its walls, not at the floor above.
Combat heating and air leaks
To combat these heating and air leaks, sophisticated energy savings retrofitters often concentrate on basement and attic work. They are trying to block the main heat loss and air leak pathways up through the building. To locate the heating and air leaks you must hire a qualified professional to find and remedy them. That is most of the reasons why heat loss occur in residential homes and building today..