ventilative cooling

The Book of Proceedings of the 43^rd AIVC - 11^th TightVent - 9^th venticool Conference: "Ventilation, IEQ and health in sustainable buildings" held in Copenhagen, Denmark on 4-5 October 2023.

The Presentations at the 43^rd AIVC - 11^th TightVent - 9^th venticool Conference: "Ventilation, IEQ and health in sustainable buildings" held in Copenhagen, Denmark on 4-5 October 2023.

Buildings account for 40% of EU energy consumption and 36% of the energy related greenhouse gas emissions at present. Consequently, the net zero target set by Energy Performance of Building’s Directive by 2050 for building stock is ambitious to achieve. The often default design choice to adopt mechanical cooling in non-domestic buildings highlights the lack of robust decision support tools or frameworks available to designers to properly evaluate ventilative cooling as a realistic alternative.

As a result of the new initiatives and regulations towards nearly zero energy buildings, designers are more frequently exploiting the cooling potential of the climate to reduce overheating and improve indoor well-being of people. At early stage of design, climate analysis is particularly useful for determining the most cost-effective passive cooling methods, such as ventilative cooling. However, besides the external climate conditions, building energy uses are characterized by occupancy pattern and needs, envelope characteristics and internal loads.

Low energy buildings are highly insulated and airtight and therefore subject to overheating risks, where Ventilative Cooling (VC) could be a relevant solution 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 widely used as a key element when designing buildings to cope with overheating to assist improving thermal comfort, but can also improve the Indoor Air Quality due to higher ventilation rates in the cooling season.

Overheating in school buildings is likely to lead to a negative learning performance experience for occupants in these settings. In Ireland, school buildings are primarily naturally ventilated, given the relative increases in external mean temperatures that are projected to have negative effects on the potential of natural ventilative cooling going forward, it is important to assess what the current overheating status is in these buildings. Existing work has already highlighted the lack of measurement data on overheating in low energy school buildings.

Embedding robust yet accessible frameworks to evaluate ventilative cooling potential during the early/concept design stages for building practitioners can help in reducing the performance gap as well as avoiding vulnerability “lock-in” from design decisions that are based on poor or inadequate information. The challenge is to develop performance based evaluation methods that recognise the tacit approach to design in practice. Often design is iterative, non-linear and multi-agent.

The growing challenges of climate change, urbanization, and increased energy demand have underscored the critical need for sustainable and resilient cooling solutions in buildings. In response to this pressing global issue, the International Energy Agency's Energy in Buildings and Communities (IEA EBC) Annex 80 was initiated to address the multifaceted aspects of resilient cooling in the built environment. Annex 80 seeks to provide valuable insights into resilient cooling systems and their indicators, offering a pathway towards a more sustainable and adaptable future...

This paper investigates the impact of ventilative cooling in residential buildings constructed from light-weight cross-laminated timber. Different temperature-controlled ventilative cooling concepts such as single sided ventilation, cross-ventilation and thermal stack based chimney ventilation concepts are simulated and compared in terms of impact on indoor temperature and robustness to external conditions such as the surroundings and the building orientation.

The future needs of indoor spaces in our buildings are likely to be cooling focused. With the widespread use of air-conditioning (AC) on the horizon there is now a need to ensure our systems perform as renewables (under the relevant definitions). A key part of tackling the uptake in energy intensive AC is likely to be the balancing of AC with renewable natural and mechanical ventilative cooling (VC).