In a cold climate the most efficient technique is to insulate the walls of your crawl space and close it off from the elements by sealing all air leaks.
How to insulate floor with small crawl space.
Unless there are excessive moisture problems in the crawl space use unfaced fiberglass batts to insulate the walls.
This type of crawl space also allows insulation with an r value of 19 installed in the floor joist if the crawl space and has a permanently installed dehumidifier.
This is also known as fiberglass insulation.
However the insulation needs to be treated with a fire retardant.
It is probably the most well known type of insulation.
Department of energy recommends r 11 3 insulation under floors in warm climates and an r 25 6 to 8 in cold climates.
Proper crawl space insulation also can prevent your crawl space from becoming a moist environment that grows and harbors mold and mildew controlling crawl space temperature and moisture is a dual process that works toward a common goal.
They are small about 6 or 8 inches long and you will find them near the top of the crawl space.
If your space has them avoid adding insulation to the crawl space walls.
Insulation also helps to preserve the air quality and reduce energy costs.
Without insulation heat and cool air are easily lost through the floor.
Be sure to.
Vents present in some crawl spaces are intended to provide air circulation that removes odors and moisture.
This type of insulation allows for conditioned air to be introduced into the crawl space.
There are two types of crawl spaces ventilated and unventilated and each requires its own form of insulation.
Insulation is to keep heat from moving from one place to another so if the crawl space is heated then the insulation is not needed.
A temperate lower area that will keep upper floors warm while your home s foundation remains in sound condition.
That s especially true when heating ducts or pipes pass through the space.
How to insulate your crawl space.
These are rolled sections meant to fit between studs in walls or in the case of a crawl space the joists supporting the floor of the house.
If as you say the floor is only dirt covered with a vapor barrier then there would be heat loss there.
That way plumbing pipes and hvac ducts are protected from freezing temps helping to conserve energy.
To take the chill out of a crawl space it s usually best to insulate the exterior masonry walls rather than the underside of the floor above.
Fiberglass insulation batts or rolls are the most economical and easiest diy choice for insulating between the floor joist in a crawl space.