The following critical limitations are mentioned in the work performed by IEA ECB Annex 62 Ventilative Cooling [1]:
Impact of climate change on the cooling potential
In the next few decades, in Europe (from South to North), extended periods with negligible to very low night cooling potential are expected to become more frequent. However cooling by night-time ventilation is likely to remain an attractive option in the transition seasons (considering that the cooling season will tend to start earlier in spring and end later in autumn).
Impact of urban environment (heat island and reduced natural driving forces)
The urban environment has a negative impact on the ventilative cooling potential and also imposes constraints for the use of natural driving forces. Urban environments have typically lower wind speeds, higher temperatures at night and higher noise and pollution levels (see below).
- Outdoor Noise levels
Outdoor noise levels in the urban environment can be a major barrier for application of ventilative cooling by natural driving forces and methods for estimating noise levels in urban canyons is needed to assess the potential as well as to assess the risk that occupants will close windows to keep out noise but also compromise the ventilative cooling strategy.
- Outdoor air pollution
Key outdoor pollutions like NO2, SO2, CO2, O3 and suspended particulate matter PM are usually measured continuously in larger urban environments and are often considered as a major barrier for application of natural ventilative cooling. Along the same line, ventilative cooling by natural driving forces might not be suitable to use during pollen season considering occupants with allergies.
Other barriers
Ventilative cooling by natural driving forces (i.e. night ventilation) might not be suitable to use because of safety concerns as well as during extreme weather (i.e. wind & rain).
References
[1] Kolokotroni, M., Heiselberg, P., Ventilative Cooling. STATE-OF-THE-ART REVIEW, IEA EBC Annex 62, Aalborg University: Aalborg, Denmark, 2015
Posted in: Cooling, Thermal Comfort, Ventilation