Method for Evaluating an Air-Conditioning System with Natural Ventilation by Coupled Analysis of a Building Energy Simulation Tool and Computational Fluid Dynamics

In office buildings, an air-conditioning system with natural ventilation can reduce cooling loads and create a comfortable indoor environment. However, it is difficult to predict the performance of such systems and there is concern that the natural ventilation will create an uneven indoor thermal environment. In this paper, we propose a method for evaluating the performance of a natural-ventilation air-conditioning system by coupling a building energy simulation tool and computational fluid dynamics.

Assessing Thermal Resilience To Overheating In An Office Building

Overheating has become a recurring problem in airtight and highly insulated buildings even in moderate climates. This study aims to analyze thermal comfort and thermal resilience in an office building during summer and mid-seasons by means of dynamic simulations. Thermal comfort assessment shows, this office building without improvements has a ‘good’ indoor climate for 79.6% of total occupied hours.

An update on the French indoor air quality observatory recent results: focus on ventilation and perspectives

The French indoor air quality observatory (OQAI) was set up by the French authorities in 2001 with the objective to collect data on indoor pollutants in various indoor environments to be used for public policies. Funded exclusively by public funding, the OQAI is coordinated by the scientific and technical center for building (CSTB) and involved an extensive network of partners across France in charge of the field campaigns and the laboratory analyses. To date, nationwide surveys were carried out in dwellings (2003-2005), schools (2013-2017), and office buildings (2013-2017).

Effect of building and installation design on PM2.5

People spend more than 80% of their time indoors. In contrast to ambient air, no (legal) limits for indoor particulate matter exist, although there are WHO guidelines. In the Netherlands a measurement protocol to determine the PM2.5 in office buildings has been developed including 5 quality classes. However at the moment no simple guidelines or models are available which can support the design and in-use phases to predict the PM2.5 concentration in office buildings and schools.

Energy-optimal ventilation strategy outside of the operating time for passive house office buildings in cold climates

The GK environmental house is the first office building in Norway built according to the passive house concept. In such buildings, it is crucial to develop a ventilation strategy to reduce the energy use outside of the operating time. An optimal operating strategy has been developed for cold days, when the outdoor temperature falls well below 0 °C, which is presented in this paper. Indeed, these conditions correspond to the largest heat loss.

Cleanliness of air filters in the experimental passive house

An inherent element of the passive house is the system of exhaust ventilation in air supply. According to their class, air filters used in ventilation systems stop the contamination, but may also be the main source of secondary indoor contamination during long-term use.

Effect of telecommuting on energy consumption in residential and non-residential sectors

In this paper, the change of energy use by telecommuting (working at home) is simulated for  residential and office buildings by modeling the  differences in the occupants’ behavior. By summing  up these results, the change in annual energy use in  Osaka City caused by the saturation of  telecommuting is evaluated in three dissemination  scenarios for the transformation of office buildings.

Daylighting and lighting saving analysis of office buildings in north China

Energy savings by integrating the daylighting availability in the electric lighting management contributes to the realization of ‘Green Building’. This paper provides a simulation and calculation of office building in North China with RADIANCE software on the basis of theoretical analysis, which focuses on the influence of Window-to-Wall Ratio (WWR), sill height, glazing transmittance and window shape on Lighting Savings (LS). The study finds out the relationship between those window parameters and LS. The results may be reference for  designers as daylighting is involved.

On the analysis of cool roofs for cooling system efficiency

Cool roof is a well-documented passive cooling strategy for buildings in several climate conditions. The mechanism consists of the reduction of the heat load entering the roof, which is characterized by high solar reflectance and high thermal emittance. The purpose of this paper is to study the coupled effect produced by such a technology. First, the passive cooling contribution is quantified, then, the “active” contribution is investigated.

Heating energy penalties of cool roofs: the effect of snow accumulation on roof

Utilizing a cool roof is an efficient way to reduce the cooling energy use of a building. Cool roofs, however, may increase heating energy use in winter. In cold climates, during the winter the sun angle is lower, days are shorter, sky is cloudy, and most heating occur during early morning or evening hours when the solar intensity is low. In addition, the roof may be covered with snow for most of the heating season. All these lead to a lower (than what is commonly thought) winter time heating penalties for cool roofs.