natural ventilation

Climate change is a growing global concern and building stock, in particular, is responsible for the emission of greenhouse gases, largely due to its poor energy efficiency. This problem is especially serious in educational buildings, where it is necessary to encourage energy efficient retrofitting under the parameters of nearly Zero Energy Building (nZEB), an objective which in Europe has been set for 2050. This is expected to produce economic, energy saving, hygrothermal comfort and health-safety benefits.

This paper investigates the relationship between indoor air quality (IAQ) and overheating in a temperate climate in Spain (Cfb attending to Koppen-Ggeiger classification), in dwellings located in residential buildings and without cooling systems.

Occupants in residential buildings usually control natural ventilation through window openings. However, few studies have developed simple rules based on the outdoor weather forecast that can inform the occupants to predict the indoor condition by applying natural ventilation for thermal comfort and indoor air quality (IAQ). This paper describes a model based on indoor/outdoor correlations, derived through simulations using EnergyPlus and CONTAM, to help occupants maintain internal environmental quality manually or through simple controls.

In future years the frequency, duration and magnitude of extreme heat events, such as heat waves, is expected to increase due to climate change. The population is exposed to higher thermal discomfort and risk at home and, at the same time, high external temperatures make it more difficult to cool their household through natural ventilation.

In order to propose adaptive measures, research should first assess the thermal resilience of the existing residential buildings when exposed to prolonged heat stress. Poorly insulated and non-equipped buildings typical of Southern

This paper presents a thermal simulation validation study of the typical precision that a trained thermal simulation engineer can expect to obtain for the simulation of a room connected to a naturally ventilated double skin facade. The open source building thermal simulation tool EnergyPlus is used to predict air and surface temperatures in a free running weather exposed test cell.

Children spend the majority of their weekdays in classrooms that often have low indoor air quality and limited financial resources for the initial and running costs of mechanical ventilation systems. Designing effective natural ventilation (NV) systems in schools is difficult due to the intense use of the classroom spaces and the dependence of NV on building geometry and outdoor conditions. Building thermal and airflow simulation tools are fundamental to predict NV system performance in the design phase.

This paper presents a validation of airflow network (AFN) and computational fluid dynamics (CFD) simulations for a naturally ventilated office building using wind tunnel measurements as the reference for external pressure coefficients and effective airflow rate prediction. The CFD simulation model is also used to study the effect of partially open windows on the effective flow rate. This study also includes a design exercise for a naturally ventilated office building that analyses the differences in predicted average window open area for a typical weather year.

This paper presents a study of the impact of horizontal aperture separation in single-sided ventilation flows with two apertures (SS2). The study is based on wind tunnel measurements and dimensional analysis. The results show that the SS2 ventilation flow rate, scaled with incoming wind velocity and aperture area, depends on the incoming wind angle relative to the aperture façade, θ, and on the aperture separation scaled by building width, s′. For most wind angles, the ventilation flow increases as the square-root of s′.