The study doesn’t include all three forms of heat energy so it’s conclusions are incorrect. The concept that the wall reflects radiation is probably wrong but I doubt any old timers gave that much consideration. If air movement is stopped buy a wall it allows more heated air to remain and transfer heat to other objects. After an object is heated it can transfer heat to a cooler material. If the wall is heated to 400 degrees F it will radiate heat back into the area, it’s not reflected heat.
“Three ways of transferring heat energy:
All heat energy, including heat generated by fire, is transferred in different ways:
Convection spreads heat in a circular motion.
Conduction transfers heat through solid materials.
Radiation is the heat we feel coming from a fire.”
“Convection tansfers heat energy through the air (and liquids). As the air heats up, the particles move further apart and become less dense, which causes the air to rise. Cooler air below moves in and heats up, creating a circular motion. The warm air circles and heats the room.”(or your tepee or lean2)
“Conduction transfers heat energy through one substance to another when they are in direct contact. The moving molecules of a warm material can increase the energy of the molecules in a cooler material. Since particles are closer together, solids conduct heat better than liquids and gases.”
“Radiation is the heat that we feel coming from a hot object. It warms the air using heat waves (infrared waves) that radiate out from the hot object in all directions until it is absorbed by other objects. Transfer of heat by radiation travels at the speed of light and goes great distances.”
“With a log fire, the air in the room above the fire is heated and rises to create convection currents. The heat felt directly from the fire is transmitted to us through radiation. Conduction helps to keep a fire going by transferring heat energy directly from the wood to neighbouring wood in the fire.”