Posted on November 25, 2016 by Martin Holladay, GBA Advisor
During the winter, the air near your floor is cold, while the air near your ceiling is hot. Similarly, during the summer, the air conditioner keeps your first floor comfortable, while the rooms on the second floor are unbearably hot. What’s going on?
The usual answer is, “Heat rises.” But that explanation isn’t quite accurate. (It’s true that hot air rises by convection. But heat travels in all directions, including sideways and downward, by conductionMovement of heat through a material as kinetic energy is transferred from molecule to molecule; the handle of an iron skillet on the stove gets hot due to heat conduction. R-value is a measure of resistance to conductive heat flow. and radiation.)