Glossary

The ability of a material to absorb heat and store it over a prolonged period. See also ‘heat storage capacity’

Heat storage capacity, also known as heat capacity or thermal capacity, is a physical property of a material or a system that indicates how much heat energy, measured in joules, it can absorb when the temperature rises by 1°K per kg.     

The process by which heat flows from an area of higher temperature to an area of lower temperature.

Heating energy is the energy required to heat a building or a room to a pleasant and comfortable temperature. It is usually measured in units such as kilowatt-hours (kWh) and serves to maintain the room temperature at a desired level, particularly during the colder months. . Buildings are mostly heated using heating oil, natural gas, pellets or electricity. As a general rule, the calorific value of 1 m³ of natural gas is roughly equivalent to that of 1 litre of heating oil or 10 kWh of electricity (rounded up or down).

The term ‘hydrophilic’ describes a substance or surface that has a strong affinity for water and interacts well with water molecules. Blotting paper is ‘hydrophilic’.

The term ‘hydrophobic’ is used to describe a substance or surface that repels water or does not interact with water.