Also any reaction caused by heat. The amount of heat that will pass through a given amount of material in a given amount of time, and with a unit temperature difference maintained between the surfaces of the material under uniform and steady conditions. Heat transfer by direct contact from one substance to another of a lower temperature. The ability of a material to conduct heat. A percentage that indicates the available heat that is converted to useful purposes.
Thermal efficiency is used to evaluate wood-conserving stoves and numerous other devices.
Material that stores energy, although mass will also retain coolness. The thermal storage capacity of a material is a measure of the material's ability to absorb and store heat. Thermal mass in passive solar buildings is usually dense material such as brick or concrete masonry, but can also be tile, water, phase change materials, etc. Generally, the thicker the wall, the less the indoor temperature fluctuates. There are four laws, of which the first and second are most often discussed.