Understanding Heat Transfer in Cool Country Houses

Why do houses in cool countries often have black roofs?

• Black roofs are aesthetically pleasing.

• Black roofs reflect sunlight effectively.

• Black is a good absorber of heat, increasing heat gain during the day.

• Black roofs are cheaper to construct.

What is the role of air in the hollow ceiling board?

• Air increases the structural strength of the ceiling.

• Air is a good conductor of heat, increasing heat loss.

• Air helps in sound insulation.

• Air is a poor conductor of heat, reducing heat loss.

Which statement is true about the black roof's heat absorption?

• The black roof gains heat from the surroundings at night.

• The black roof neither gains nor loses heat.

• The black roof increases heat gain during the day.

• The black roof reduces heat gain during the day.

How does the air in the ceiling board affect heat transfer at night?

• It increases heat loss to the cooler air outside.

• It reduces heat loss to the cooler air outside.

• It has no effect on heat transfer.

• It increases heat gain from the outside.

Which statement about the black roof at night is correct?

• The black roof gains heat from the surroundings at night.

• The black roof loses heat to the cooler air at night.

• The black roof maintains the same temperature as during the day.

• The black roof reflects heat back into the house.