What is the rate of heat loss through an insulated wall with glass wool?

In summary, the problem involves calculating the rate of heat loss through a wall insulated with glass wool. The thermal conductivity of the glass wool is given as 0.046 W/m oC and the temperature difference across the layer is 20.0 oC. Using the equation Q/deltaT = KA * delta T/L, the correct solution is found by correctly plugging in the area, resulting in a rate of 0.92 W.
  • #1
kboykb
13
0

Homework Statement



A wall is insulated with glass wool of thermal conductivity K = 0.046 W/m oC. What is the rate of heat loss (in W) through an area 1.0 m wide by 1.5 m high, insulated with a layer of glass wool 20 cm (.2 m) thick, if the temperature difference across the layer is 20.0 oC?

Homework Equations



I think I'm just doing something wrong algebraically. I'm using Q/deltaT = KA * delta T/L

The Attempt at a Solution



Finding the area first (l*w?) = 1.0 m * .2m = .2m

Then

(0.046 * .2) * (20/.2) = .92 degrees
 
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  • #2
Do your units match up?
 
  • #3
I got it right :-) Sorry, I'm a noob. I was plugging in the wrong Area, and it was causing my number to come out wrong.

Thanks!
 

Related to What is the rate of heat loss through an insulated wall with glass wool?

1. How is the rate of heat loss calculated?

The rate of heat loss is calculated by multiplying the thermal conductivity of the material (in W/mK) by the temperature difference (in Kelvin) and dividing it by the thickness of the material (in meters).

2. What is the significance of a rate of heat loss of .92 W?

A rate of heat loss of .92 W indicates that the material has a low thermal conductivity and is therefore a good insulator. This means that it is able to resist the transfer of heat and can help maintain a stable temperature in a given space.

3. How does the rate of heat loss affect energy efficiency?

A lower rate of heat loss means that less energy is required to maintain a desired temperature, resulting in higher energy efficiency. This is especially important in buildings and homes, where reducing heat loss can lead to significant cost savings on heating and cooling.

4. Can the rate of heat loss be improved?

Yes, the rate of heat loss can be improved by using materials with lower thermal conductivity, such as insulation, or by increasing the thickness of the material. Proper installation and sealing of building materials can also help reduce heat loss.

5. What other factors can affect the rate of heat loss?

The rate of heat loss can also be affected by factors such as temperature gradients, wind speed, and humidity levels. Additionally, the type and condition of the material, as well as the presence of air pockets or gaps, can impact the rate of heat loss.

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