Depending upon where you live and how your house was built, your home may have any of several types of heating systems that help you to enjoy your interior spaces year round. Forced-air and gravity furnaces power ducted central systems, while electricity, water, or steam charge up radiant heating units. And fireplaces and pellet stoves--which create heat by burning pellets made of recycled sawdust, wood shavings, or other biomass waste materials--can be significant sources of supplemental heat.
Whenever you are dealing with home climate systems, remember that heat rises and will move from a warm place to a colder place. The greater the temperature difference, the faster the movement.