A

AEROGENERATOR
Mechanical device that converts the Kinetic Energy of an air flow into Mechanical Energy (rotation of a shaft), which is later converted into Electric Energy by a Generator.
AIR CONDITIONING SYSTEM
Combined set of equipment to satisfy one or more of the objectives of air conditioning: air ventilation, heating, cooling, humidification, dehumidification and purification. Air conditioning is the result of having all the above options available.

B

BIOFUEL
Fuel produced from Biomass.
BIOMASS
Non-fossil organic matter, of biological origin, which can be used for energy purposes, to produce Biofuels, Biogas, etc..
BLADE
Mechanical element of a wind turbine that converts the Kinetic Energy of an air flow into Mechanical Energy on the shaft of the turbine shaft.

C

CENTRALIZED SYSTEM
System in which the equipment needed for heating and cooling (and filtration, humidification and dehumidification, if any) is concentrated in an installation at a place other than the places to be heated, and the cold or heat (and humidity) are partially or completely transported by a thermal fluid to the different places to be heated or cooled.
COGENERATION
Simultaneous production of two types of energy, Heat and Electricity, from a single source of Primary Energy, Natural Gas, with higher performance than individual Heat and Electricity production systems.
COMBINED CYCLE POWER PLANT
Thermoelectric plant that produces electricity in two different thermodynamic cycles. A Petrol Turbine acts as a first generator, and the exhaust gases are reused in a second Turbine, in this case Steam, activating a second generator.
CONDUCTION
Heat transfer mechanism, characterized by the transport of heat between solid matter or fluids at rest, through their molecular structure.
CONVECTION
Heat transfer mechanism in moving fluids, which may exist naturally due to temperature differences and density, and can be forced by pumps or fans.
COP
The "Coefficient of performance" describes the nominal efficiency of a heat pump. It is most commonly used to designate efficiency in heating mode.

D

DHW - DOMESTIC HOT WATER
Drinking water heated above 35 ºC for bathing, cleaning, cooking and other specific purposes, by specific equipment for this purpose, using conventional or renewable forms of energy.

E

EMISSIVITY
The relation between an object’s thermal radiation capacity and that of a black body at the same temperature, that is, it reveals the emission power of electromagnetic radiation of a given object, as a function of wavelength.
ENERGY AUDIT
Analysis of how an installation operates in order to determine how, when, where and under what conditions energy is used, assessing possible areas of intervention to improve operating processes and rationalize consumption.
ENERGY MIX
Percentage distribution of primary energy sources in the national grid’s electricity production. Varies annually, namely depending on hydraulicity.
ENERGY RATIONALIZATION PLAN
Set of measures for energy rationalization (reduction of energy consumption or costs) drawn up following an energy audit, organised and serialized based on their enforceability and their economic viability.
ENTHALPY
Thermodynamic quantity that expresses the internal energy of a system during a given process or reaction.
ENTROPY
Thermodynamic quantity that expresses the "disorder" of a system.
EXERGY
Thermodynamic quantity that represents the maximum useful work of a system as it interacts with the environment.

F

FINAL ENERGY
Energy made available to users in different forms (e.g. electricity, petrol, and firewood) and generally expressed in units with commercial significance (kilowatt-hour, cubic meters, kilograms, etc.)

G

H

HEAT EXCHANGER
Mechanical device that transfers heat from one fluid in motion to another, in motion or otherwise, without contact between the two, through convection and conduction.
HEAT PUMP
High performance reversible mechanical device that draws heat from a low temperature source (cold source) and provides this heat to a hot source. Mainly used in two modes: (1) the heating station draws "heat" from the outside into the inside of the house, heating it; (2) the cooling station removes heat from the inside to the outside of the house.
HOUSE PERMEABILITY
Characterizes air tightness to leaks, in particular the energy lost through these leaks. It is quantified in rph (renewals per hour).

I

J

JOULE
Unit of energy, work and amount of heat in the International System of Units (SI). It is equivalent to the work produced by a force of 1 Newton to move a point object 1 metre.

K

L

M

MECHANICAL VENTILATION
Renewal of indoor air by air extraction and blowing of external air, or mixing new air coming from the outside and return air using a system of ducts and fans to propel the air.

N

NATURAL VENTILATION
Renovation of indoor air with fresh outdoor air using only openings in the surroundings which have a suitable area, are self-controlled or manually regulated, and natural mechanisms of air flow based on wind and temperature differences.
NOMINAL GLOBAL PRIMARY ENERGY REQUIREMENTS (Ntc)
Parameter that expresses the amount of primary energy corresponding to the weighted sum of nominal heating (Nic), cooling (Nvc), and the heating of sanitary water (Nac), considering the adopted systems or, should these not be defined, conventional reference systems, and the current standards of use for such systems.
NOMINAL USEFUL ENERGY REQUIRED FOR COOLING (Nvc)
Parameter that expresses the amount of useful energy required to permanently maintain a building or individual unit at an indoor reference temperature during the heating season, under nominal conditions.
NOMINAL USEFUL ENERGY REQUIRED FOR HEATING (Nic)
Parameter that expresses the amount of useful energy required to permanently maintain a building or individual unit at an indoor reference temperature during the heating season, under nominal conditions.
NOMINAL USEFUL ENERGY REQUIRED FOR HEATING SANITARY WATER (Nac)
Parameter that expresses the amount of useful energy required to heat the average annual reference volume of sanitary water to a temperature of 60 ºC, under nominal conditions.

O

P

PCI
Low Calorific Power. Defines the amount of energy (Joule) released in the complete combustion of a fuel unit (Petrol, Diesel, Natural Gas) assuming the evaporation of reaction products, mainly water.
PHOTOVOLTAIC CELL
Device containing semiconductor materials such as monocrystalline silicon that produces electrical energy from solar radiation.
PRIMARY ENERGY
Energy resource found in nature (oil, hydropower, wind, biomass, solar, ...) Usually expressed in terms of the mass of oil equivalent (kilogram of oil equivalent - kgep - or tonne of oil equivalent - toe). Some forms of primary energy (natural gas, firewood, sun) can also be made available directly to users (final energy).

Q

QAI CORRECTIVE ACTION PLAN
Set of measures to achieve concentrations of pollutants within a building or the individual units inside a building below the maximum reference values, in order to ensure hygiene levels and safeguard the health of its occupants.

R

RCCTE
Regulations on the Characteristics of the Thermal Behaviour of Buildings
RENEWABLE ENERGY
Energy from the sun (in the form of light, thermal or photovoltaic), biomass, wind, geothermal, hydropower or waves and tides.
RSECE
Regulations on Energy Systems for Air Conditioning in Buildings.

S

SOLAR COLLECTOR
Device that collects solar radiation from the sun, to convert it into thermal energy, which is transported by a thermal fluid (air, water, refrigerant) for specific purposes.
SOLAR FRACTION
Percentage of Hot Water provided by the installed solar system.

T

THERMAL BRIDGE
A thermal bridge is a part of the building’s structure with thermal characteristics that differ significantly from the surrounding structure. A thermal bridge generally implies lower thermal resistance which allows greater heat exchange.
THERMAL CONDUCTIVITY
A typical thermal property of a homogeneous material that equals the amount of heat per unit time that passes through a layer of this material with unitary thickness and area per unit of temperature difference between its two faces.
THERMAL INSULATOR
A material with thermal conductivity smaller than 0.065 W/m.ºC, or whose thermal resistance is larger than 0.30 m2.ºC/W.
 
TROMBE WALL
Trombe walls are very thick walls (high thermal inertia) painted in a dark colour to store energy from solar radiation during the day. Through small holes in the base and top, trombe walls provide heat inside the house during the day, by Natural Convection, and by irradiation at night.

U

USEFUL ENERGY
Energy made available to the consumer (Heat, Cold) after the final conversion by equipment in the home (Boiler, Air Conditioning Equipment).

V

W

X

Y

Z