case studies

Overheating is an unwanted consequence of modern building designs and internal gains that will be aggravated by the effects of climate change on local climates within urban and suburban areas. To minimise the energy cost of limiting overheating several different approaches exist for passive cooling dissipation techniques. Free cooling by ventilation, or Ventilative Cooling, (VC), is a generally accepted effective, energy efficient, mitigation strategy to building overheating. There are many factors that influence the design and selection of suitable VC strategies.

One of the most commonly used strategies to reduce the heating demand in low energy buildings is reducing the leakage level of the building envelope. Dedicated ventilation systems are then installed to compensate for the reduced air change rate in an energy efficient way. Most occupants, however, operate their ventilation system at very low flow rates. Together with the emission of bio-effluents, linked to the presence of the occupants, moisture production related to household activities is one of the most important sources of indoor air pollution in dwellings.

This work evaluates the performance of different façade solutions, comparing simulation results of glass type and (internal and/or external) solar protection, in the cities of São Paulo and Rio de Janeiro, Brazil. For the simulations, it was considered as

Since the beginning of this decade, natural ventilation in office buildings is receiving specific interest. There are two sorts of application. Natural ventilation can be a strategy for indoor air quality control. Besides it can be used as night ventilation during warm or hot periods. In this case the objective is to cool down the thermal mass and improve the thermal summer comfort. The EC JOULE NatVent project wanted to identify the barriers to the application of natural ventilation in office-type buildings in moderate and cold climates and to provide solutions.

Natural ventilation can be a part of a strategy for a good indoor air quality. It can also be a way to realise night time ventilation during warm periods. In this latter case, the aim is to cool down the thermal mass of the building to obtain a better thermal comfort during daytime. Night time ventilation requires high ventilation rates and sufficient accessible thermal mass. The ventilation openings have to be well designed to avoid undesirable effects like rain, pollution and burglary.

The initial findings of a project initiated in the University of Coimbra and dealing with the conjugated influence of multiple stressors in riding passengers are presented in this paper. A field study in public transportation buses was conducted, having been the subjective responses of the occupants collected and the physical parameters related to the thermal comfort, noise, vibration and air quality acquired. In the questionnaires, the PMV scale was used to evaluate the thermal aspects and, for the other stressors, a five-point scale, from very uncomfortable to very comfortable, was used.

The coupling of simulation methods is an interesting way to get improved or new results concerning thermal conditions in ventilated, heated, and air conditioned rooms. Some results are given for an investigation of a room in a low energy house by building simulation including CFO and the simulation of several heating systems. Comparative studies are done in two different ways. The first way serves to get results about different heating systems concerning thermal comfort and energy consumption and the second one to study the influence of the CFO calculation on the results.

In predicting the thermal environment of an indoor space affected seriously by the outdoor weather like an atrium using natural ventilation, it is essential to grasp the impact of the external outdoor weather precisely. This report describes the result of the analysis of the outdorr and indoor region including solar radiation analysis considering the date and hour, latitude and longitude taking the atrium under construction in Kyoto as an example.