00:01
We can use the formula for calculating the heat transfer rate through a composite wall.
00:31
So w equals to t1 minus t2 is divided by sigma r multiply a where w is the rate of heat transfer heat transfer through the wall and t1 is indoor temperature.
01:23
Temperature in kelvin t2 equals to outdoor temperature.
01:39
R is the thermal resistance of each layer and a is the cross -sectional area of each layer.
02:21
Sigma denotes the sum of all the layers thermal resistance.
02:26
Let's calculate the thermal resistance denoted by r for each layer.
02:41
Foam layer r low dash foam equals to thickness is divided by k is multiply a equals to 0 .02 is divided by 0 .026 w by m k is multiply 4 meter is multiply 6 meter thickness is approximately 0 .64 k by w.
03:40
K by w is thermal resistance of each layer.
03:49
Plaster layer r low dash plaster equals to thickness is divided by k multiply a equals to 0 .03 meter is divided by 0 .22 w by m k is multiply 4 meter is multiply 6 meter.
04:38
So approximately is 0 .24 k by w.
04:46
Plaster layer r low dash brick equals to thickness is divided by k is multiply a equals to 0 .15 meter divided by 0 .72 w by m k is multiply 4 meter is multiply 6 meter is the time.
05:35
R brick is approximately 0 .07 k by w.
05:45
Now let's calculate the thermal resistance of the total wall...