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For example, if 250 J of heat energy is added to a copper gear with a thermal mass of 38.46 J/°C, its temperature will rise by 6.50 °C. If the body consists of a homogeneous material with sufficiently known physical properties, the thermal mass is simply the mass of material present times the specific heat capacity of that material.
Concrete has a relatively high thermal mass, meaning that it takes a long time to respond to changes in ambient temperature. [9] This is a disadvantage when rooms are heated intermittently and require a quick response, as it takes longer to warm the entire building, including the slab. However, the high thermal mass is an advantage in climates ...
Concrete has a very low coefficient of thermal expansion, and as it matures concrete shrinks. All concrete structures will crack to some extent, due to shrinkage and tension. Concrete which is subjected to long-duration forces is prone to creep. The density of concrete varies, but is around 2,400 kilograms per cubic metre (150 lb/cu ft). [1]
The thermal mass properties of concrete increase the efficiency of both residential and commercial buildings. By storing and releasing the energy needed for heating or cooling, concrete's thermal mass delivers year-round benefits by reducing temperature swings inside and minimizing heating and cooling costs. [ 116 ]
For example, Paraffin has very large molecules and thus a high heat capacity per mole, but as a substance it does not have remarkable heat capacity in terms of volume, mass, or atom-mol (which is just 1.41 R per mole of atoms, or less than half of most solids, in terms of heat capacity per atom).
Mass concrete is defined by American Concrete Institute Committee 207 as "any volume of concrete with dimensions large enough to require that measures be taken to cope with the generation of heat from the hydration of cement and attendant volume change to minimize cracking."
The low thermal diffusivity (1.48 × 10 −7 m 2 /s) and effusivity [286 J/(m 2 ⋅K⋅s −1/2)] of hempcrete reduce the ability of hempcrete to activate the thermal mass. Hemp concrete has a low thermal conductivity, ranging from 0.06 to 0.6 W m −1 K −1 , [ 24 ] [ 15 ] [ 25 ] a total porosity of 68–80% [ 24 ] [ 26 ] and a density of 200 ...
The simplest rule of thumb is that thermal mass area should have an area of 5 to 10 times the surface area of the direct-gain collector (glass) area. [20] Solid thermal mass (e.g., concrete, masonry, stone, etc.) should be relatively thin, no more than about 4 in (100 mm) thick.