Glossary of energy-related terms

Most common energy-related terms collected in one place.

Glossary of energy-related terms

On this page you can find all the key terms frequently used in relation to energy, ventilation, air-conditioning, heating, cooling, humidifying and dehumidifying of buildings.

  • Adiabatic cooling / evaporative cooling
  • COP (Coefficient of Performance)
  • EER (Energy Efficiency Rating)
  • Hybrid device
  • Chiller
  • Refrigerant / coolant
  • Evaporator / vapouriser
  • Condenser
  • Latent heat
  • Line supply
  • Mechanical cooling system / compressor cooling system
  • Free cooling
  • Regeneration
  • Regenerator
  • Heat recovery
  • Recuperator / heat exchanger
  • Sensible heat
  • Split cooling system
  • Heat pump

Adiabatic cooling / evaporative cooling

Adiabatic or evaporative cooling is a cooling mode, where tiny water droplets are sprayed into the air. The droplets then evaporate and consume the heat energy of air, and thereby cool the air. Adiabatic cooling is carried out without any additional energy consumption (the minimum amount of energy used for the water circulation can be neglected). It is a wholly natural process. Evaporative air-conditioning devices further reduce the costs of cooling of buildings. The following devices have series-mounted adiabatic cooling: Menerga Adsolair, Menerga Adconair and Menerga Adcoolair.

COP (Coefficient of Performance)

Coefficient of performance (heat pumps, cooling systems or air-conditioning devices) is the ratio between the obtained heating power and the consumed electric power. It tells us how much heat energy is generated by a heating device in relation to the electric energy it consumes. Higher factor indicates higher system performance and lower operating costs.

Example: Heating system COP = 5.0
Meaning: For 1 kW of consumed electric energy we produce 5 kW of heat energy.

EER (Energy Efficiency Rating)

Energy Efficiency Rating (heat pumps, cooling systems or air-conditioning devices) is the ratio between the obtained cooling power and the consumed electric power. It tells us how much cooling energy is generated by an air-conditioning device in relation to the electric energy it consumes. Higher factor indicates higher system performance and lower operating costs.

Example: Cooling system ERP = 5.0
Meaning: For 1 kW of consumed electric energy we produce 5 kW of cooling energy.

Hybrid devices

These devices connect two previously unconnected systems or units into one compact and integrated system. Combining a heat pump and a chiller into a single system, Menerga Rewatemp is a perfect example of such a device.

Chiller

A chiller is a device that cools cooling water, which is circulating through cooling elements. The cooling water that comes from the chiller is heated by the warm indoor air, while the room itself is cooled. The chiller then cools the warm water and releases it back into the room that requires cooling. Read more about chillers.

Refrigerant / coolant

It is a cooling agent, used by heat pumps and chillers as a medium for raising and lowing the energy potential of the environment. Commonly used coolant is Freon gas.

Evaporator / vapouriser

An evaporator/vapouriser is a part of a heat pump or a mechanical refrigerator. The gases are evaporated where the heat energy is being discharged through air or water.

Condenser

A condenser is a part of a heat pump or a mechanical refrigerator. The gases are condensed (liquefied) where the heat energy is being discharged through air or water.

Latent heat

Latent heat is a type of energy that is released or absorbed by the moisture in the air when it transits into a different energy state.

Line supply

Line supply is an air supply in the form of long and narrow slots that can be build into the floor or ceiling.

Mechanical cooling system / compressor cooling system

A cooling system based on the mechanical work of a compressor (compression of gas).

Free cooling

The process of free cooling is carried out when the ambient air temperature is lower than indoor air temperature. During this process, the energy recovery rate varies from 0% to 100%.

Regeneration

During the process of regeneration, the fresh ambient air is simultaneously heated and humidified. This is especially important in the winter, when the indoor air is usually dry. It should also be observed that the regenerative ventilation system allows slow and permanent dehydration of buildings. In this way we can prevent retention of moisture, mold, and, consequently, early building deterioration.

Regenerator

A type of heat exchanger where heated and cooled air flows through the heat accumulator; as it heats the accumulator, the heated air itself is cooled. Next, the heat energy of the accumulator is transferred to the cool air. Consequently, the cool air is heated and the accumulator cooled. There are stable and rotary regenerators. Menerga Resolair devices have a built-in regenerator.

Heat recovery

Heat recovery is the process of returning heat into the building. Heat recovery is provided by a recuperator in an air-conditioning device. Inside a recuperator, the energy of ”used” indoor air is transferred to the fresh ambient air, but the two types of air are not mixed together! Thus, the space is filled with fresh air, onto which the energy of the exhaust air had been transferred. The consumed air, which had been deprived of heat, is eliminated from the building. Heat recovery decreases the need for heating / cooling and thereby substantially reduces operating costs.

Recuperator / heat exchanger

A recuperator is an integral part of an air-conditioning device, comprised of parallel plates of plastic, through which the heat from a warmer medium is transferred to the colder medium; the media flows of air, water or other substances can be concurrent, countercurrent or perpendicular (90 degree cross-flow), and do not mix together; the recuperator can be a single, a double or a three-stage device, which means it has one, two or three recuperative units. Menerga Dosolair and Menerga Adsolair devices have a built-in cross flow recuperator; Menerga Adconair devices have a built-in countercurrent recuperator; Menerga Trisolair devices has a built-in three-stage recuperator.

Sensible heat

Sensible heat is the heat we can feel; heat is comprised of a sensible part (sensitive heat), which can be perceived as lower or higher temperature, and of a latent part, which represent the moisture in the air.

Split cooling system

A split cooling system is a cooling system comprised of a cooling part (evaporator) of a mechanical cooling system (inside the building), and a compressor-condenser unit (outside the building). The split cooling systems only rotate the indoor air and do not provide ventilation. Free ventilation (opening of windows) is therefore still needed, in order to ventilate the spaces. This decreases the efficiency of system performance and increases operating costs.

Heat pump

Heat pump is a device with a built-in evaporator, with the help of which it extracts heat from air, water or surrounding area in order to heat an energy-saving building.