Archives: Glossary

  • Renewable Energy

    Energy from sources that naturally replenish, such as sunlight, wind, water and ambient heat.

  • Render

    An external finish applied to walls. It may be used as part of an external wall insulation system.

  • Relative Humidity

    The amount of moisture in the air compared with the maximum amount it could hold at that temperature.

  • Refrigeration Cycle

    The process used by heat pumps, fridges and air conditioners to move heat. The main stages are compression, condensation, expansion and evaporation.

  • Refrigerant

    The working fluid inside a heat pump or refrigeration system. It absorbs and releases heat as it changes pressure and state.

  • RdSAP

    Reduced Data Standard Assessment Procedure. The method used to assess the energy performance of existing UK homes for EPCs.

  • Radiator

    A heat emitter that transfers heat from hot water into a room.

  • Quality Assurance

    Checks carried out to make sure retrofit work has been assessed, designed, installed and recorded correctly.

  • Psi Value

    A measure of heat loss at junctions between building elements, such as around windows or where walls meet floors.

  • Primary Energy

    Energy measured before losses from generation, conversion and distribution are considered.