Ventilative cooling to reduce overheating in buildings in ventilation related standards and legislation in the context of well-being, sustainability and energy.


Ventilative cooling (VC) is widely used as a key element when designing a building to cope with overheating. This part focuses on the indoor climate aspects. However, the focus towards well-being, sustainability and energy use are now on the agenda in many countries. VC can, when designed correctly, tap into these three aspects and promote buildings with higher degree of well-being, be a part of the sustainability agenda and result in a reduced energy use. It should be noted that there to some extent is an overlap of the three mentioned aspects; well-being, sustainability and energy use.

VC can under the right conditions be a very good main alternative, supplementary solution to mechanical cooling systems.

Low energy buildings are highly insulated and airtight and therefore subject to overheating risks, where VC might be a relevant solution. VC is an application (distribution in time and space) of air flow rates to reduce cooling loads and overheating in spaces using outside air driven by natural, mechanical or hybrid ventilation strategies. Ventilative cooling reduces overheating in both existing and new buildings – being both a sustainable and energy efficient solution to improve indoor well-being, hereunder thermal comfort (State-of-the-art-review, Kolokotroni et al., 2015). VC is further an important topic supported by the International Energy Agency (IEA) – where the project, IEA Annex 62 Ventilative cooling had a special focus on this area finishing the project in 2018.

The purpose of this workshop is to evaluate and discuss how ventilative cooling is a mean to reduce overheating in buildings to achieve good well-being in ventilation related standards and legislation in the context of:

  • Well-being
  • Sustainability
  • Energy

Generally, ventilative cooling is a good alternative to mechanical cooling in buildings, under the right conditions. To allow for VC to be treated better in standards both at the design stage, where initial calculations of e.g. the natural forces are made as well as, at more detailed stages where more detailed calculations are needed, it is important that several parameters are taken into account, such as (Status and recommendations for better implementation of ventilative cooling in standards, legislation and compliance tools, Plesner, 2018):

  • Assessment of overheating, e.g.:
    • Utilizing thermal comfort indicators, including adaptive temperature sensation
    • Utilizing energy performance indicators
  • Assessment of natural and mechanical ventilative cooling
  • Assessment of night cooling
  • Calculation methods that fairly treat natural ventilative cooling for determination of air flow rates including g. the dynamics of varying ventilation and the effects of location, area and control of openings


To give the participants an insight into how “Ventilative cooling” fits into the three tracks:

  • VC in terms of Well-being
    • Framing well-being
    • Intensive ventilation to boost air flow rates
    • IEA Annex 80
    • Integration in International standards and legislation
  • VC in terms of Sustainability
    • Renewable energy solution used for cooling in terms of Renewable Energy directive (REDII)
    • Integration in International standards and legislation
    • Resilience to power outtages (fx. Allowing manual solutions also)
  • VC in terms of Energy use
    • Hourly calculations. vs. monthly calculations (required in EPBD) 
    • Ventilative cooling may reduce the need for energy use for mechanical cooling
    • Integration in International standards and legislation

To enable the participants to take away key recommendations on the correct understanding of how VC is to be viewed and implemented in future buildings.

To highlight that VC is a good alternative instead of using mechanical cooling in buildings


  • Introduction to Topical Session – Christoffer Plesner, VELUX A/S, Denmark & Jannick Roth, WindowMaster International A/S, Denmark

Well-being track:

  • Upcoming European and International technical documents on “Ventilative cooling systems – Design” in CEN/ISO – Christoffer Plesner, VELUX A/S, Denmark & Jannick Roth, WindowMaster International A/S, Denmark.
  • How is VC a part of resilient cooling strategy and what to be aware of in the early-stage design? Paul O’Sullivan, MeSSO Research at Munster Technological University, Ireland.
  • How does well-being and the revision of EN 16798-1 fits into VC? Bjarne W. Olesen, ICIEE, Technical University of Denmark, Denmark.

Sustainability track:

  • Is VC a renewable energy solution and how does it fit into the sustainability agenda? Ivan Pollet, Renson, Belgium.
  • Is VC a relevant and future proof cooling solution? Peter Holzer, Operating Agent EBC Annex 80, Institute of Building Research & Innovation, Austria.

Energy track:

  • Why choose hourly calculation procedures – and the relation to the VC potential tool? Dick van Dijk. EPB Center. Netherlands


  • Questions and open Discussion. Facilitated by Christoffer Plesner, VELUX A/S, Denmark & Jannick Roth, WindowMaster International A/S, Denmark.


  • Christoffer Plesner, VELUX A/S, Denmark 
  • Jannick K. Roth, WindowMaster International A/S, Denmark 


  • 90 minutes