A Carpenter Builds An Exterior House Wall

4. Does the carpenter make an exterior wall with 3.0 cm thick wooden plywood and S-shaped plywood on the outside? 3

4. A carpenter builds an exterior wall with a single layer.

3.0 cm thick and one layer of wood

2.2 cm thick styrofoam insulation on inner wall

Area. In wood k = 0.080 W / m.K and

Styrofoam has k = 0.0I0W / m.K. Inner surface

Temperature 19.0 ° C and outer surface

The temperature is 10.0 C. (a) What is temperature?

At what rate does wood get styrofoam? (B)

How much heat flow per square meter?

This wall?

We don't see heat transfer from air here.

a = 0.03 m thick layer of wood

kw = 0.08 W / mK Thermal conductivity of wood

Above = 10 ° C = 263 K outside temperature

b = 0.022 m thick polystyrene

ks = 0.01 W / mK The thermal conductivity of styrofoam

Ti = 19 ° C = 292 K indoor temperature

Tx = temperature at the point of contact with polystyrene wood

The rate of heat transfer through the layers of wood and styrofoam should be the same:

ks (Ti Tx) / b = kw (Tx To) / a

Tx (kw / a + ks / b) = ks Ti / b + kw Ke / a

Tx = (0.01 * 292 / 0.022 + 0.08 * 263 / 0.03) / (0.08 / 0.03 + 0.01 / 0.022) = 267 K.

Tx = 6 ° C

Heat flow per square meter is:

Â¦ = Â ”T / R where R is the total thermal resistance of the wall R = Rw + Rs

Rw The thermal resistance of wood sheet Rw = a / A * kw = 0.03 / 0.08 = 0.375 K / W

Polystyrene layer thermal resistance Rs = b / A * ks = 0.022 / 0.01 = 2.2 K / W

A = 1 square meter

R = 2,575 K / W

Â ”T = 19 (10) = 29 K.

¦ = 29 / 2.575 = 11.26 W.

A Carpenter Builds An Exterior House Wall

Use of polystyrene
I will try to be with you. You won't bother me. If they build dams, that's fine as long as they don't use the wood I made. If he needed something in the forest the other animals could be there, or me, so I invaded his area ...

A Carpenter Builds An Exterior House Wall