glossary
Welcome to our glossary of useful terms and expressions related to sustainability in the m&e sector.
You can search for definitions and explanations using our alphabetical links below or simply by scrolling through.
We hope you find these helpful and you will see as you navigate other pages on the site that each time a glossary term occurs there is a live link to its definition here.
Please contact the site editor Ewen Rose if there are other subjects you think we should include.
- Global warming
- The gradual increase in the earth's average temperature caused by the greenhouse effect.
- Green roofs
- Growing roof systems utilizing a specialised undercarriage for the waterproof membrane and excess water removal. Various types of vegetation are set into a special growing medium and help to replace displaced vegetation in the building footprint as well as greatly reducing the heat island effect. Green roofs can create pleasant gardens and help regulate stormwater flow.
- Greenhouse effect
- The heating that occurs when gases such as carbon dioxide trap heat escaping from the Earth and radiate it back to the surface; so-called because the gases are transparent to sunlight but not to heat and thus act like the glass in a greenhouse.
The means by which a proportion of the radiated heat from the Sun is trapped within the atmosphere by 'greenhouse gases'. - Greenhouse gas
Gases in the atmosphere that absorb heat radiated by the Earth and prevent this heat being lost into space. The main greenhouse gases are water vapour, methane, halocarbons (CFCs, HFCs, etc) and carbon dioxide.
- Greywater
- Wastewater from household baths, washing machines, and other sources (excluding human waste) that is recycled especially for use in gardening or for flushing toilets.
- Ground source heat pumps
- Systems that use refrigeration technology to convert low grade heat from the ground into usable energy that can heat a building. Ground source heat pumps typically attain a CoP (Coefficient of Performance) of between 2.5 and 4. Reversible heat pumps can be used to also provide cooling in the summer.