Heat pumps - Vapor compression systems

At a time when we are talking about saving energy and reducing greenhouse gas emissions, the heat pump (PAC) appears to be a technology capable of making a significant contribution to meeting tomorrow's major challenges.

In France, the building sector accounts for almost half of final energy consumption and one-fifth of greenhouse gas emissions; the energies used are mainly fossil fuels (gas and fuel oil). But industrial applications can also benefit from the use of such technologies.

Derived from refrigeration applications, heat pumps have long been limited in their applications to fairly low heating temperature levels. This made it difficult, if not impossible, to use them to replace fossil-fuel boilers. The preferred sector was therefore new-build. What's more, economic conditions relating to the price of traditional energies and the immaturity of the market did not favor their development over the past decades.

Recent developments in new technologies, driven in particular by regulations governing refrigerants, should see new products appear on the market in the next few years. Manufactured in large series, they will be capable of heating water to temperature levels suitable for rehabilitation projects, as well as for domestic hot water production.

We can only hope that the energy and environmental potential of heat pumps, which has been under-exploited in recent years, will be fully recognized. Heat pumps, which are capable of harnessing the low-temperature, renewable energy contained in elements such as air, water and soil, should therefore become a major element in our energy landscape.

Coupling them with other renewable energy systems, such as solar thermal energy, should also be one of tomorrow's research priorities, in order to promote synergies and complementarity.

After recalling, in this first part [BE 9 620], the theoretical principles of operation as well as the various possible designs and technologies for PACs, we will then discuss in the second part the various possible applications for heat pumps. A section will be devoted to the market and product performance.

Finally, we'll look at compression machines with heat engines, absorption systems and open-ended systems similar to heat pumps.