Why is aerogel used as an insulating material in skylights?

[felipe douglas]

Homework Statement

Your house will have several skylights. To minimize heat flow, each skylight will have two transparent panes separated by an intermediate layer. Since visibility through the skylight isn't important, the gap between the panes will be filled with aerogel: a porous, ultralight translucent material that is almost 100% gas. Why not just use the gas alone? Why add the porous framework of the aerogel?

a. During the cold winter, natural buoyance causes gas to rise from the cooler lower pane to the hotter upper pane. Many convection cells develop in between the panes and heat is carried efficiently from the upper pane to the lower pane. The porous framework prevents such convection.
b. During the cold winter, natural buoyance causes gas to rise from the hotter lower pane to the colder upper pan. Many convection cells develop in between the panes and heat is carried efficiently from the lower pane to the upper pane. The porous framework prevents such convection.
c. During the hot summer, natural buoyance causes gas to rise from the hotter lower pane to the colder upper pane. Many convection cells develop in between the panes and heat is carried efficiently from the lower pane to the upper pane. The porous framework prevents such convection.
d. During the hot summer, natural buoyance causes gas to rise from the cooler lower pane to the hotter upper pane. Many convection cells develop in between the panes and heat is carried efficiently from the upper pane to the lower pane. The porous framework prevents such convection

Homework Equations

none

The Attempt at a Solution

C? because Natural buoyancy causes hotter air to rise in colder air.[/B]

 

[DaveC426913]

Start with examining the difference between the four options.
a] winter: cool air near lower pane, hot air near upper pane
b] winter: hotter air near lower pane, cool air near upper pane
c] summer: hotter air near lower pane, cool air near upper pane
d] summer: cool air near lower pane, hot air near upper pane

Do these all make sense? Can you rule any out?

 

[felipe douglas]

Start with examining the difference between the four options.
a] winter: cool air near lower pane, hot air near upper pane
b] winter: hotter air near lower pane, cool air near upper pane
c] summer: hotter air near lower pane, cool air near upper pane
d] summer: cool air near lower pane, hot air near upper pane

Do these all make sense? Can you rule any out?

can definitely rule out D

 

[felipe douglas]

im thinking B or C? since the air is hotter in the lower pane..

 

[haruspex]

im thinking B or C? since the air is hotter in the lower pane..

What exactly is the difference in the wording between b and c? Which of them would be a reason for the aerogel?

 

[felipe douglas]

What exactly is the difference in the wording between b and c? Which of them would be a reason for the aerogel?

since aerogel helps to insulate heat, it would be helpful during the winter? (B?)

 

[haruspex]

since aerogel helps to insulate heat, it would be helpful during the winter? (B?)

Insulation can be useful in the summer too. Why doesn't the explanation in C make sense?