What does insulation do? How does it make my house warmer?

Insulation doesn’t “heat” an area, it simply slows down heat movement through building materials. Since heat will always move to a colder source, in cold climates, insulation slows the heat from leaving the house and in hot climates insulation slows down the hot outside air from entering the cool inside. The result in both climates is energy saved by keeping the air conditioner or the furnace from operating as often.
There are many types and forms of insulation, and some …