Archives: Glossary

  • Flue

    A pipe or duct that safely removes combustion gases from a boiler, stove or fire.

  • Flat Roof Insulation

    Insulation added to a flat roof. It may be installed above, below or within the roof structure depending on the roof type.

  • F-Gas

    Fluorinated greenhouse gas used in some refrigeration, air conditioning and heat pump systems. Some F-gases have high global warming potential.

  • Fan Coil Unit

    A heat emitter that uses a fan to move air across a heating or cooling coil.

  • Fabric First

    A retrofit approach that improves the building fabric first, such as insulation, airtightness and ventilation, before changing the heating system.

  • Extractor Fan

    A fan that removes moist or stale air from rooms such as bathrooms, kitchens and utility rooms.

  • External Wall Insulation

    Insulation fixed to the outside of external walls and finished with render, cladding or another weatherproof layer.

  • Expansion Valve

    In a heat pump or refrigeration cycle, the expansion valve reduces the refrigerant pressure and temperature before it enters the evaporator.

  • Expansion Vessel

    A vessel in a sealed heating system that absorbs expansion as water heats up.

  • Energy Saving Measure

    A retrofit improvement designed to reduce energy use, such as insulation, heating controls, glazing or low-carbon heating.