Insulation in Winter Coats

As winter is coming to an end, many people wonder if their coats were effective at keeping them warm on those frigid days. Coats keep a person warm because of their insulation. However, that brings up the questions of, what is insulation and why does it work?

Insulation is the material inside the coat that helps trap your body heat. Winter coats use 2 main types of insulation. One of which is down insulation, from goose or duck plumage (the fluffy mid-layer underneath the feathers). The second type is synthetic insulation, which consists of sheets of polyester fibers which mimic plumage. The polyester fibers are arranged in different patterns and intertwined with one another to create air pockets. Occasionally one will find a third type which is a mix between down and synthetic insulation. The image below compares what the down insulation looks like and the synthetic insulation looks like.

The technology and science behind down and synthetic insulation is quite simple. The plumage or synthetic material will trap pockets of air which in turn traps one's body heat allowing the body to remain at a comfortable temperature. The significance of keeping the body at a comfortable temperature is because the cold air from the outside lowers the body temperature. The insulation keeps the heat trapped near the body as a result of the air pockets created by the down or synthetic insulator.


If one wanted to decide whether their jacket was effective they would have to take note of the outside weather and their ability to generate heat. Each insulated winter coat has a different level of warmth; and these warmth levels are often referred to as “fill power” or amount of plumage that are put into the coat. As more plumage is put into a coat more tiny air pockets are formed hence, it creates a warmer coat. The high end and warmest coat’s fill power range from 750-900 fill, this type of coat is ideal for one who lives with cold winters and does not generate alot of body heat. However, this type of winter jacket may not be the perfect fit for some who lives where there are warm winters and can generate alot of body heat. So, if a person’s winter coat is insulated with a proper amount of quality insulation, their coat is going to be a great warm and cozy jacket.