Passive cooling should be priority for net zero says energy expert

Passive cooling should be a foremost priority for sustainable building design alongside the use of more efficient technologies, an energy efficiency expert has argued.

Dr Satish Kumar of the India-based Alliance for an Energy Efficient Economy (AEEE) said it was vital that efforts to lower overall cooling loads must be a central focus of global efforts to create lower carbon buildings as part of the economic response to the ongoing Covid-19 pandemic.

Dr Kumar said that passive design measures should be considered the starting point when planning for thermal comfort in homes, offices and other buildings. More innovative and efficient systems should then be introduced to address remaining cooling needs where needed.

He said, “I think if you do it well, not only can you reduce the cooling demand, but in many cases you can also completely eliminate the need for refrigerant-based cooling.”

Dr Kumar was speaking as part of a panel discussion held earlier this month to coincide with the launch of a new report from the UN-backed Cool Coalition initiative focused on how sustainable cooling and cold chain strategies can be factored into Covid-19 recovery plans.

He said there were already many examples around the world of building plans that consider passive cooling as a first step in curbing temperature gain in buildings.

Dr Kumar added, “We feel that you incorporate shading, ventilation and insulation strategies in the building design process and then think about if you can use fans, coolers or hybrid technologies.”

Hybrid approach

Projects already being developed under the US$1 million Global Cooling Prize were cited by Dr Kumar as an example of the innovation being made in the field of hybrid cooling solutions that use little or no refrigerant with global warming potential.

Hybrid technologies currently being developed as part of the prize include systems that can switch between vapour compression refrigeration, direct evaporative cooling and ventilation functions depending on the outside climate,

Dr Kumar said the direction of hybrid innovation under the project reflected a belief within industry that better design practices and codes, alongside adaptive thermal comfort standards and technology, will allow for much more energy efficient and effective cooling.

He argued, “I think you need to not always design for 22 deg C (68 deg F), but you can design instead for 26.7 deg C (78 deg F) and people will be perfectly fine. Passive building design becomes a much more powerful tool if you expand the thermal comfort envelope.”

“So I think this is absolutely the right way to go – do the building design first, then go for the most efficient technology and then think about renewable energy systems. It has to be done in this manner.”