While there are additional considerations such as venting and moisture problems to take into account when you insulate under floors the united states department of energy recommends an r 25 rating in cold climates and an r 11 in warmer parts of the country.
Roof insulation ratings.
The higher the r value the better the thermal performance of the insulation.
Improved insulation is a good step toward improving building efficiency particularly since the atlanta based american society of heating refrigerating and air conditioning engineers ashrae increased minimum roof insulation levels in 2007 in its standard 90 1 the first increase in 18 years and if that isn t enough to spur someone into action.
See the department of energy s doe ranges for recommended levels of insulation below.
A recent mckinsey co.
The r value per inch for different types of insulation varies depending on the.
Having the correct amount of attic insulation can help you maintain a comfortable temperature throughout your home and help save money on your energy bills plus prevent major issues like ice dams in the winter.
Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces.
R value is a measure of insulation s ability to resist heat traveling through it.
Measure the area needing insulation.
Insulation ratings are measured in r values per inch of thickness.
As a benchmark one inch of solid wood has an r value of 1.
If you think you re among the 90 of us homes that are under insulated 1 performing a simple insulation inspection will help you determine your insulation needs.
If your current insulation is only 5 inches deep you ll need to add seven inches of insulation to achieve the 12 inch r 38 rating.
R 38 is the industry standard and the minimum thickness for r 38 is 12 inches.
In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and an inch of blown cellulose in an attic has an r value of 3 2 3 7.
Measure the depth of your current insulation.
Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system.
The r value is a measure of the insulation batt s resistance to heat flow also known as thermal resistance.
Typically a higher insulation r rating means better climate control and better.
The greater the r value the greater the resistance to heat transfer and the greater the insulating effect and subsequent energy savings.
Insulation r values vary based on the type thickness and density of the insulation material.
Calculate additional insulation needed.
