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.
How to insulate floor with small crawl space.
A temperate lower area that will keep upper floors warm while your home s foundation remains in sound condition.
Unless there are excessive moisture problems in the crawl space use unfaced fiberglass batts to insulate the walls.
It is probably the most well known type of insulation.
That way plumbing pipes and hvac ducts are protected from freezing temps helping to conserve energy.
Vents present in some crawl spaces are intended to provide air circulation that removes odors and moisture.
However the insulation needs to be treated with a fire retardant.
The goal however is the same.
This is also known as fiberglass insulation.
Fiberglass insulation batts or rolls are the most economical and easiest diy choice for insulating between the floor joist in a crawl space.
Department of energy recommends r 11 3 insulation under floors in warm climates and an r 25 6 to 8 in cold climates.
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.
Be sure to.
This type of insulation allows for conditioned air to be introduced into the crawl space.
Insulation also helps to preserve the air quality and reduce energy costs.
They are small about 6 or 8 inches long and you will find them near the top of the crawl space.
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.
To enclose the space in a thermal envelope.
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.
If as you say the floor is only dirt covered with a vapor barrier then there would be heat loss there.
How to insulate your crawl space.
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.
If your space has them avoid adding insulation to the crawl space walls.
Without insulation heat and cool air are easily lost through the floor.
That doesn t mean it s a problem but it isn t needed.