We sometimes use acronyms and other terms with which you may not be familiar. Here is a list of some of them. We hope you find it helpful.

Action on Energy (sometimes AonE)
This is a project run by a partnership of Cambridgeshire District Councils to help people save energy at home, for example enhancing take up of the Green Deal. They have engaged Climate Energy Ltd as their delivery partner. See
ASHP (Air Source Heat Pump)
A heating system which draws heat from the outside air. See Heat Pumps
CCF (Cambridge Carbon Footprint)
This is local charity that aims to help people reduce their carbon footprint. There is a lot of overlap with Transition Cambridge both in goals and in membership. We often collaborate on events. see
Carbon Trust
This is a company that gives advice about saving energy to commercial, industrial and public sector clients. See
CHP (Combined Heat and Power)
A heating system (gas powered) which also generates electricity. This is more efficient than generating electricity in a gas power station because the power station also makes heat but this is wasted.
DECC (Department of Energy and Climate Change)
This is the government department that manages the Green Deal and various other financial incentives to do with Energy.
EAHP (Exhaust Air Heat Pump)
A heating system which recycles heat from the inside air before exhausting it to the outside. See Heat Pumps
ECO (Energy Companies Obligation)
This is the scheme whereby electricity companies provide grants to households for energy efficiency measures. This is tied into the Green Deal
EST (Energy Saving Trust)
This is a social enterprise that gives advice about saving energy at home. See
FiT (Feed in Tariff)
This is a financial incentive to encourage people to install renewable electricity systems such as solar electricity panels. See also our Finance page.
GDHIF (Green Deal Home Improvement Fund)
A grant which was part of the Green Deal. DECC closed this abruptly on July 24th because it had used up its budget.
Green Deal
This is a government scheme to promote energy efficiency and renewable energy in homes and businesses in the UK. See our Green Deal FAQ
GSHP (Ground Source Heat Pump)
A heating system which draws heat from the ground. See Heat Pumps-HeatPumpFAQ
Internal heat gains
This is heat generated inside your building as a side effect of living in it. This includes heat from the appliances you are using (TV, tumble dryers, kettles etc.) and also heat generated by our own bodies. An adult sitting quietly typically generates about 100W. If you are active you can generate 2-3 times this.
kW (kilo-watt)
This is a unit of power - the 'rate of doing work'. For example, kettles typically use 2-3 kW whereas a CFL light bulb probably takes 10-20 W. Watts applies to heat as well as electricity. Your boiler probably generates up to 30 kW when it is running.
kWh (kilo-watt-hour)
A unit of energy (1 kW for 1 hour or 2 kW for 30 minutes, and so on). You will see kWh on your energy bills for both electricity and gas.
MLEI (Mobilising Low Energy Investment)
This is a Cambridgeshire County Council scheme to attract investment for delivering energy efficiency in the county. See
MVHR (Mechanical Ventilation with Heat Recovery)
A system which provides ventilation while capturing heat from the outgoing air and using it to warm air coming in. This can be in single room extractors or a whole house ducted system. See our advice on ventilation
Passive heat gains
these are heat gains that you get without actually turning on the heating. They include solar gains and internal gains such as from appliances.
Passivhaus standard
This is a standard for energy efficient buildings originating in Germany. It requires lots of insulation, minimal thermal bridging and good air tightness. Ventilation is usually provided by MVHR. Passivhaus buildings need very little additional heating beyond passive heat gains.
PV (Photovoltaic)
A shorthand for solar electricity panels see [[our solar electricity FAQ->PVFAQ]
RHI (Renewable Heat Incentive)
This is a financial incentive to encourage people to install renewable heat systems such as solar hot water panels and heat pumps. See also our Finance page.
Solar gain
This is the heat that comes into a building from sunshine. Mostly it comes through windows but you can also get a lot of heat through, for example, a flat roof in summer. In winter solar gain is usually helpful but in summer time it can be a problem.
Solar thermal
A shorthand for solar panels that provide hot water, see our solar hot water FAQ
SPEP (Sustainable Parish Energy Partnership)
This is a S. Cambridgeshire District Council project supporting sustainability groups in the villages in the area. There are common resources, a newsletter, and sometimes funding. See
SWI Solid wall insulation
Walls without cavities, or where the cavities are hard to fill, can still be improved with insulation See Solid wall insulation
Thermal bridge
This is where heat bypasses the insulation in your wall, roof or whatever and finds an easier way out, such as along a metal service pipe or through a metal wall tie. Thermal bridges can be a significant route for heat loss if the building is otherwise well insulated.
Thermal mass
This is a measure of how much heat it takes to warm something up - and how much heat it has to lose to cool down. The units are energy/temperature difference. Generally speaking, heavy materials such as stone, brick and concrete have high thermal mass whereas light, insulating materials have very low thermal mass.