Gaspar Martín_ACTECIR: The technological transition in air conditioning requires time for all stakeholders to adapt

How can air-conditioning and refrigeration help improve the energy management of buildings?

These comfort needs have traditionally been major energy consumers in buildings, as the main source of energy demand in residential buildings and in some services buildings, along with lighting. This is becoming no longer the case, especially since the publication in 2019 of the current CTE (Spanish Technical Building Code), which has reduced the energy demand for air conditioning in buildings by around 40%, due to the stricter requirements regarding the type of enclosures and insulation defined in HE1 of the aforementioned CTE.

The natural trend is towards making buildings zero-energy to meet air conditioning demands. This is likely to be legislated for new buildings in the next update of the CTE, which must integrate the criteria set out in in the Energy Performance of Buildings Directive (EPBD). I believe, however, that the main difficulty lies in what actions will have to be taken throughout the existing building stock to reduce that energy demand and consumption for air conditioning and cooling. 

How is the inclusion of renewable energy in these areas evolving?

Linked to the previous question, it’s clear that the first thing to do is take action on the passive parts of the building, in order to reduce the thermal demand as much as possible. Once this is achieved, this demand should be met mainly or entirely by renewable energy.

The logical transition is towards the use of electric air-conditioning systems, mainly based on aerothermal heat pumps, supported by photovoltaic production systems. This is easily integrated into the new building; in fact, it is becoming the main trend.

What about refurbishments?

On the refurbishment side, where we generally start from an original boiler, the use of these electrical systems is not always easy, and may both technically and economically unfeasible. Here the solution may lie in the use of hybrid boiler/heat pump systems, which would allow the building to be partly decarbonised in a more logical and applicable way.

Looking to the future, it also remains to be seen how the diffusion of renewable gases will evolve, with the likes of green hydrogen and, above all and on a more massive scale, biomethane, as well as how they fit into legislation so that they can be considered renewable energies.

What other aspects stand out in the modernisation of air-conditioning and refrigeration systems?

As mentioned above, modernisation in equipment is backed up by the use of predominantly electric technologies: heat pumps and solar photovoltaic. This requires adaptation and retraining process for the professionals responsible for designing and installing this equipment, many of them with experience and knowledge of the classic heating sector, based on the use of gas combustion equipment. These heat pumps use refrigerants, which also require professionals not only electrically skilled, but who also know how to handle these refrigerant gases.

There is also a technological evolution in the regulation and control of air-conditioning installations. Heat pump systems usually require more knowledge at this point in order to correctly configure and parametrise the installation. This becomes even more complex if we talk about hybrid equipment combining two technologies such as boiler and heat pump.

What's your opinion of the new European legislation, and the deadlines and targets?

I believe that the legislative framework that is being defined in Europe, with the main focus on the decarbonisation of buildings on the continent, is necessary and uncontroversial in terms of ensuring environmental sustainability. What I am perhaps more critical of is whether the deadlines and objectives to be achieved in that time are realistic and achievable. We must remember that all this technological transition requires time to adapt for all stakeholders in the marketing and distribution chain of air conditioning products: manufacturers, brand ambassadors, installers and the building owners themselves.

It may be the case that more is being run than this sector can take on and absorb in that period of time, without going into whether there are economically sufficient resources to do everything necessary in the specific field of energy refurbishment: improving building cladding, replacing existing equipment with renewable systems, etc.