Heatiator ECO-ADV-WS22 Thermal Conductivity k value, Thermal Resistance R value, Calculatons

D. Calculating Alternate Floor Protection Material

Thermal Conductivity: k value

The k value indicates the amount of heat (in BTU’s) that will flow in 1 hour throught 1 square foot of a uniform material 1 inch thick for each degree (F) of temperature difference from one side of the material to the other. The LOWER the k factor means less heat is being conducted through the non-combustible material to the combustible material beneath it. The k value of a material must be equal or smaller then the required k value to be accept- able.

(BTU) (inch) (foot2 (hour) (oF)

Thermal Resistance: R value

The R value is a measure of a material’s resisteance to heat transfer. R value is convenient when more than one material is used since you can add the R values together, whereas you can not do this for k value. The HIGHER the R factor means less heat is being conducted through the non-combustible material to the combustible material beneath it. The R value of a material must be equal or larger then the required R value to be accept- able.

Converting k to R:

Divide 1 by k and multiply the results times th thickness in inches of the material.

R = 1/k x inches of thickness

Converting R to k:

Divide the inches of thickness by R. k = inches of thickness/R

Calculatons:

Example: Floor protection requires k value of .84, 3/4 inch thick.

Alternative material has a k value of .6 and is 3/4 inch thick.

Divide .6 by .75 = k value of .80. This k value is smaller than .84 and therefore is acceptable.

32 Heatilator • ECO-ADV-WS22 • 7057-128C • August 13, 2010