What is the stack effect and how does it affect my Minnesota home?
Warm air is buoyant, so in winter it rises and leaks out through gaps high in the home, around attic penetrations and upper windows. As that air escapes, it must be replaced, drawing cold air in through lower leaks at the rim joist and basement.
This circulation has real consequences. It increases heat loss and energy bills, causes uncomfortable lower-level drafts, and importantly, the suction at the base of the home pulls soil gas, including radon, in through foundation cracks and the slab.
Air sealing counters the stack effect. Sealing attic-plane leaks reduces the air escaping at the top, and sealing the rim joist and basement reduces infiltration at the bottom. Together this improves comfort, lowers heating costs, and can even help reduce radon entry.
