MATERIALS

Specific Heat Capacity (c)

Heat required to raise 1 kg of a material by 1 °C, in J/kg·K. High c × density = high thermal mass = slow temperature swings indoors.

Also calledspecific heatspecific heat capacityheat capacityc valuethermal mass coefficient

Related on InfraLens

CODES

IS 11239 IS 3346

Definition

Specific heat capacity (symbol c) is the amount of heat needed to raise the temperature of 1 kg of material by 1 °C. Units: J/kg·K. Drives thermal mass — materials with high c × ρ (specific heat × density) absorb and release heat slowly, dampening indoor temperature swings. Concrete and stone have moderate c (~880-900 J/kg·K) but high density → high thermal mass, useful for passive cooling in hot-dry climates. Water has the highest c at 4186 J/kg·K — used in water-tank thermal storage.

Typical values

Water4186 J/kg·K

Concrete880-900 J/kg·K

Brick840 J/kg·K

Stone (granite)790 J/kg·K

Steel490 J/kg·K

Wood1700 J/kg·K

Air1005 J/kg·K

Gypsum board1090 J/kg·K

Where used

Thermal mass calculation for passive cooling
Phase-change material design
Night-purge cooling strategies
HVAC dynamic-simulation

Acceptance / threshold

Per IS 11239 + ECBC dynamic-simulation Annexure: c-values from referenced standards or manufacturer test data.

Site example

A 230 mm brick wall of 1 m² area weighs 1900 kg/m³ × 0.23 = 437 kg/m². Its heat capacity per m² = 437 × 840 = 367 kJ/m²K. To raise the wall by 1 °C requires 367 kJ — that's why thick masonry stays cool through the morning heat and only warms by evening.

Frequently asked

What is specific heat capacity?

Specific heat capacity (c) is the heat needed to raise 1 kg of material by 1 °C, in J/kg·K. Drives thermal mass — high c × density = slow temperature swings indoors.

Why does concrete have high thermal mass?

Concrete combines moderate c (880 J/kg·K) with high density (2400 kg/m³). Volumetric heat capacity = c × ρ = ~2110 kJ/m³K — much higher than wood (~720) or insulation (~30). Thick concrete walls slow indoor temperature swings by hours.

Related materials terms

Ordinary Portland Cement (OPC)

33/43/53 grade Portland cement. 53 most common for structural use.

Portland Pozzolana Cement (PPC)

Cement blended with fly ash. More durable than OPC.

Portland Slag Cement (PSC)

Cement blended with blast furnace slag

Aggregates (Fine & Coarse)

Coarse (10-40mm) and fine (sand) aggregates per IS 383

Sand (River / M-Sand)

Fine aggregate. River sand or manufactured sand.

Brick / Block Masonry