Heat pumps and their use as a renewable energy source
The term "heat pump" is becoming increasingly popular as the use of this technology spreads in buildings and homes. The general purpose and concept of heat pumps can be understood, but how are they defined? What is the principle of operation of heat pump technology as a solution?
Introduction
Heat pumps are part of environmentally friendly technologies that use renewable energy. These are mentioned in the European Directives on the Use of Renewable Energy (RES), Energy Performance of Buildings (EPBD) and Energy Products (ErP). Furthermore, heat pumps are also mentioned in the Directive on the promotion of the use of energy from renewable sources (2009/28 / EC, RES Directive). The directive recognizes technology that uses renewable energy sources from air, water and soil. Heat pumps are considered an excellent opportunity to reach the EU target for a reliable, affordable and sustainable energy supplier.
What is the definition of heat pumps?
In Directive 2010/31 / EU of the European Parliament and of the Council of 19 May 2010 on the energy performance of buildings (EPBD) recast, "heat pump" means a machine, device or installation that transfers heat from the natural environment, such as be air, water or soil in buildings or industrial applications, reversing the natural flow of heat so that it flows from a lower temperature to a higher one. For reversible heat pumps, the heat in the building can also be moved to the natural environment.
This definition of a heat pump is based on the physical characteristics of energy transfer. This definition is wide open to any machine, device or installation that will do the job of energy transfer. It leaves the door open to all existing or future technologies and we hope that improvements will emerge for innovative and more energy efficient models. Apart from all the listed natural energy sources, the residual heat is not mentioned, but it offers great opportunities to recover energy from air or water.
To achieve energy transfer, auxiliary energy is needed depending on the technology: there are electric heat pumps, gas-driven or gas-absorbing. The ratio of auxiliary energy consumption to heat transfer is currently around one third depending on the technology used, the efficiency of the device and the temperature conditions. Obviously, a minimum level of efficiency should be set to ensure low energy consumption, so that a heat pump deserves to be considered a sustainable energy device.
In conditions of extreme cold, the efficiency of air heat pumps decreases dramatically. Therefore, an alternative heating system must come into play. This alternative may not come from a renewable energy source and will therefore reduce the overall efficiency of heat production during the year and the sustainability of the environment. How to approach this problem for the qualification of heat pumps?
Adding the above considerations and keeping the arguments and style of the EU, a broader and broader definition can be suggested: A 'heat pump' is a machine, device or installation that uses renewable natural energy sources from aerothermal, geothermal or hydrothermal or waste heat processed non-naturally from water or air and which transfers it to buildings or industrial applications by reversing the natural flow of heat so that it flows from a lower useful temperature to a higher one. To conduct this process, a primary supply of electricity, gas or fuel is required. In extreme weather conditions, an additional heating device must compensate for the reduced heat production from the heat pumps. Only heat pumps with a power which significantly exceeds the primary energy required to supply them and the additional energy of the heater must be considered. Obviously, a minimum level of efficiency should be set to ensure low energy consumption for the heat pump to be considered a sustainable energy device. When heat pumps are reversible, the heat in the building can also be moved to the natural environment. This should be taken into account and may be integrated into the efficiency factor. Do not multiply production systems in the same infrastructure.
Due to the complexity and multiple parameters to consider for heat pumps, calculating their efficiency is a real challenge. The efficiency will also be subject to the local climatic conditions in which the device will be installed. This challenge is part of the long road to reducing the impact on the environment, by choosing the best heat pump technology or selecting the right equipment.
Heat Pump Solutions and Systems
We, the HVAC engineers, at E.E.B.C. we take into account all aspects related to the challenges of heat pump systems and we will always choose the best technologies and we will select only the appropriate equipment for each project.
