Duct tape is made of polyethylene, a plastic that is not very good at preventing the flow of heat. Additionally, duct tape is often not applied evenly, which can create gaps that allow heat to escape. For these reasons, duct tape is not a good choice for insulating a home or other structure.

Here are some better options for insulation:

* Fiberglass: Fiberglass is a type of insulation made of tiny glass fibers. It is a good insulator because it traps air between the fibers, which prevents the flow of heat.

* Cellulose: Cellulose is a type of insulation made of recycled paper. It is a good insulator because it is lightweight and fluffy, which allows it to trap air.

* Spray foam: Spray foam is a type of insulation that is applied in liquid form and then expands to fill the space it is applied to. It is a good insulator because it conforms to the shape of the surface it is applied to, creating a tight seal that prevents the flow of heat.