natural ventilation

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).

Over time with thermal and energy regulations, buildings are increasingly insulated and airtight to control better the heat exchanges between the indoor and outdoor environments. The primary function of the mechanical ventilation system is to ensure healthy air by diluting odours and humidity with fresh air. However, in many situations, windows opening can be much more effective in terms of thermal comfort, air quality, or release heat loads due to a higher air change rate than the mechanical ventilation system itself.

In this paper, a new mathematical model was developed experimentally to quantify the air volume flow by natural ventilation through window tilt opening. The experiment was carried out with two test facades in a laboratory building in Aachen, Germany. The test facades are equipped with windows in two different dimensions, and they are located under real weather conditions. The modelling data were determined by means of more than 70 tracer gas measurements with CO2.

Indoor air quality (IAQ) control in educative centres, where students spend most of their time, is essential. The presence of high levels of contaminants can impact the academic performance of the students and, ultimately, their health. A study has been carried out to assess the IAQ of higher education classrooms with natural ventilation in order to quantify the exposure of the occupants to certain contaminants during the cold season. CO2, PM10, PM2.5, PM1.0, and volatile organic compounds (VOC) have been measured.

Portable air cleaners have demonstrated their effectiveness in reducing indoor PM concentrations. Common rating systems assume the air cleaner is in a room having limited air exchange with ambient air and the rest of the building. In this analysis, we model conditions in which people operate air cleaners in rooms with some natural ventilation. METHODS: A simplified mass balance model was developed for a 50 m3 room within a 350 m3 home, assuming well-mixed spaces, homogeneous infiltration, and applying the LBLX ventilation model.

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