ventilation

A universal lumped model is developed with the aim to predict the thermal performance of Double Skin facade. Three modules – ventilation, heat transfer and penetration - are coupled to comprehensively describe the energy and mass transfer processes. The unknown parameters, resistance coefficient and heat convection coefficient, are discussed and estimated. The influences of cavity shading position, cavity depth and ventilation height on energy performances are analyzed at the end of the paper based on the simulation results.

The deep hot hyperarid valley between Israel and Jordan presents unique design and construction challenges in terms of energy conservation and thermal comfort. Winters are relatively mild, summers are extremely hot during the day and at night the air temperature remains above 25°C.  Such conditions present real challenges in this sparsely populated yet rapidly developing region. Such development depends on the ability to provide acceptable indoor environments at a low energy investment.

Nowadays, important efforts are made to reduce the residential building energy consumption. In this context, a growing interest for heat recovery ventilation has been observed during the last decades. The present paper focuses on a new single room ventilation with heat recovery. Double flow ventilation is achieved through the integration of the unit into windows ledges. The developed device is particularly suitable compared to traditional centralized heat recovery ventilation units for retrofitted houses due to the absence of air extracting and air pulsing ducts through the house. 

Heat recovery ventilation became an unavoidable element of a passive or nearly zero energy building in Northern and Central Europe countries. Airtightness standards became very tight so that the building is compatible with this ventilation system. As frosting of heat recovery unit consumes a lot of electrical energy, a buried pipe system to smooth air temperature variations became also a necessary system in order to avoid defrosting.

As a consequence of the energy and environmental issues, it is necessary to reduce the energy consumption of buildings. So, the air tightness of building envelopes is being improved and the air change rate due to infiltration is decreasing. It is then even more important than in the past that the buildings are equipped with well designed and working ventilation systems in order that the air renewal within buildings is ensured. In this context, the market of balanced ventilation systems with heat recovery for dwellings is growing. 

In order to improve the quality of ventilation systems, assessments are widely used. In this paper, 3 main assessment levels are distinguished based on the number of ventilation systems to be assessed and the assessment objective.

Few studies focus on commercial low-rise buildings which are often characterized by low-cost constructions materials and weak energy performances. For these large volumes, the heat transfers with the roof and the ground are prevalent. In this article, we show how the analysis of heat transfers through both the roof and the ground can achieve their thermal performance. The roof design and its opening systems is a key factor of the thermal and lighting performance.

Worldwide the food system is responsible for 33% of GHG emissions. It is estimated that by 2050, total food production should be 70% more than current food production levels.   In the UK, food chain is responsible for around 18% of final energy use and 20% of GHG emissions. Estimates indicate that energy savings of the order of 50% are achievable in food chains by appropriate technology changes in food production, processing, packaging, transportation, and consumption.  

The exposure of children to indoor air pollutants in school classrooms might cause them adverse health effects. In order to confront this issue, the in-depth study and evaluation of the indoor air quality in classrooms is necessary. The aims of this study are to characterize the environmental factors that affect indoor air quality.

Air quality in the office room areas, as well as their energy demands for heating and cooling are directly depended on the ventilation levels in those rooms. Specifically, high internal air quality requires high levels of ventilation and therefore high energy demands. On the other hand, high energy savings can be accomplished by full building impermeability, which means low to none ventilation and at the same time low air quality.