Use of thermal mass in different climates Thermal mass

1 use of thermal mass in different climates

1.1 temperate , cold temperate climates

1.1.1 solar-exposed thermal mass
1.1.2 thermal mass limiting summertime overheating


1.2 hot, arid climates (e.g. desert)
1.3 hot humid climates (e.g. sub-tropical , tropical)

use of thermal mass in different climates

the correct use , application of thermal mass dependent on prevailing climate in district.

temperate , cold temperate climates
solar-exposed thermal mass

thermal mass ideally placed within building , situated still can exposed low-angle winter sunlight (via windows) insulated heat loss. in summer same thermal mass should obscured higher-angle summer sunlight in order prevent overheating of structure.

the thermal mass warmed passively sun or additionally internal heating systems during day. thermal energy stored in mass released interior during night. essential used in conjunction standard principles of passive solar design.

any form of thermal mass can used. concrete slab foundation either left exposed or covered conductive materials, e.g. tiles, 1 easy solution. novel method place masonry facade of timber-framed house on inside ( reverse-brick veneer ). thermal mass in situation best applied on large area rather in large volumes or thicknesses. 7.5–10 cm (3-4 ) adequate.

since important source of thermal energy sun, ratio of glazing thermal mass important factor consider. various formulas have been devised determine this. general rule, additional solar-exposed thermal mass needs applied in ratio 6:1 8:1 area of sun-facing (north-facing in southern hemisphere or south-facing in northern hemisphere) glazing above 7% of total floor area. example, 200 m house 20 m of sun-facing glazing has 10% of glazing total floor area; 6 m of glazing require additional thermal mass. therefore, using 6:1 8:1 ratio above, additional 36–48 m of solar-exposed thermal mass required. exact requirements vary climate climate.

a modern school classroom natural ventilation opening windows , exposed thermal mass solid concrete floor soffit control summertime temperatures


thermal mass limiting summertime overheating

thermal mass ideally placed within building shielded direct solar gain exposed building occupants. therefore commonly associated solid concrete floor slabs in naturally ventilated or low-energy mechanically ventilated buildings concrete soffit left exposed occupied space.

during day heat gained sun, occupants of building, , electrical lighting , equipment, causing air temperatures within space increase, heat absorbed exposed concrete slab above, limiting temperature rise within space within acceptable levels human thermal comfort. in addition lower surface temperature of concrete slab absorbs radiant heat directly occupants, benefiting thermal comfort.

by end of day slab has in turn warmed up, , now, external temperatures decrease, heat can released , slab cooled down, ready start of next day. regeneration process effective if building ventilation system operated @ night carry away heat slab. in naturally ventilated buildings normal provide automated window openings facilitate process automatically.

hot, arid climates (e.g. desert)

an adobe walled building in santa fe, new mexico

this classical use of thermal mass. examples include adobe or rammed earth houses. function highly dependent on marked diurnal temperature variations. wall predominantly acts retard heat transfer exterior interior during day. high volumetric heat capacity , thickness prevents thermal energy reaching inner surface. when temperatures fall @ night, walls re-radiate thermal energy night sky. in application important such walls massive prevent heat transfer interior.

hot humid climates (e.g. sub-tropical , tropical)

the use of thermal mass challenging in environment night temperatures remain elevated. use temporary heat sink. however, needs strategically located prevent overheating. should placed in area not directly exposed solar gain , allows adequate ventilation @ night carry away stored energy without increasing internal temperatures further. if used @ should used in judicious amounts , again not in large thicknesses.