Thermal conductivity, measured in watts per meter per degree Celsius (W/m·K), is a measure of a material's ability to conduct heat. The lower the thermal conductivity, the better a material is at insulating. Examples of materials with low thermal conductivity include fiberglass, cellulose, and spray foam insulation.
Specific heat, measured in joules per kilogram per degree Celsius (J/kg·K), is a measure of a material's ability to absorb and store heat. The higher the specific heat, the more heat a material can absorb before its temperature increases. Examples of materials with high specific heat include water, concrete, and brick.
Density, measured in kilograms per cubic meter (kg/m³), is a measure of a material's weight per unit volume. The higher the density, the more heat a material can store. Examples of materials with high density include concrete and brick.
When building or renovating a home, it's important to consider the thermal properties of the materials used. For example, using insulation with a low thermal conductivity can help keep a home cooler in the summer and warmer in the winter by slowing down the transfer of heat through the walls. Similarly, using materials with a high specific heat and density, such as concrete or brick, can help absorb and store heat, making a home more energy-efficient.
Here's a comparison of thermal properties of common building materials:
Fiberglass insulation: Thermal conductivity: 0.040 W/m·K; Specific heat: 840 J/kg·K; Density: 32 kg/m³
Cellulose insulation: Thermal conductivity: 0.040 W/m·K; Specific heat: 820 J/kg·K; Density: 40 kg/m³
Spray foam insulation: Thermal conductivity: 0.025 W/m·K; Specific heat: 1210 J/kg·K; Density: 32 kg/m³
Concrete: Thermal conductivity: 1.75 W/m·K; Specific heat: 910 J/kg·K; Density: 2380 kg/m³
Brick: Thermal conductivity: 0.72 W/m·K; Specific heat: 880 J/kg·K; Density: 1920 kg/m³
From the above comparison, Spray foam insulation is the best material with low thermal conductivity, high specific heat and density, followed by cellulose insulation and fiberglass insulation. Concrete and brick are also good options for their high specific heat and density, but they have higher thermal conductivity, which makes them less effective as insulation.
In summary, when building or renovating a home, it's important to consider the thermal properties of the materials used in order to create an energy-efficient and comfortable living space. Materials with low thermal conductivity, high specific heat and density, such as spray foam insulation, cellulose insulation and fiberglass insulation, are ideal for insulation. Concrete and brick, while having high specific heat and density, are less effective as insulation due to their higher thermal conductivity.