Design and performance of ventilative cooling: a review of principals, strategies and components from International case studies

Overheating is an unwanted consequence of modern building designs and internal gains that will be aggravated by the effects of climate change on local climates within urban and suburban areas. To minimise the energy cost of limiting overheating several different approaches exist for passive cooling dissipation techniques. Free cooling by ventilation, or Ventilative Cooling, (VC), is a generally accepted effective, energy efficient, mitigation strategy to building overheating. There are many factors that influence the design and selection of suitable VC strategies. Obtaining quantitative data about the spectrum of solutions employed across the range of suitable VC applications can be difficult and high in collaborative effort. A recent International Energy Agency project gathered information about well documented case studies of buildings with VC and investigated the existence of synergies in design, selection and simulation of solutions as well as any heterogeneous patterns in the adoption of VC principles and VC system component characteristics. This paper presents the aggregated data for 14 international case studies, provides a review of the VC systems adopted and design methods applied to ensure successful performance for different building types and climates. Various methods for VC system sizing at each stage of the design process are discussed along with the design criteria adopted in each case. Values for the percentage opening area to floor area ratio, a key metric for benchmarking the sizing of ventilation openings are presented and discussed. Further, a recommended range for this fundamental design parameter is suggested. Demonstrated implementation of control strategies for different types of VC solutions is also reviewed and discussed. Similarities in lessons learned were found to exist across multiple case studies. Finally, a synopsis of the key lessons learned during the design and operation phases of the case studies is also presented and reviewed.