VC

The present paper addresses experiences with infiltration and ventilation in the Active House concept, based on the Active House Specification and realized Active Houses. The Active House Specification is based on a holistic view on buildings including Comfort, Energy and Environment. It uses functional requirements to indoor air quality and thermal comfort, and does not have component requirements to airtightness or specific ventilation solutions. Experiences from realised Active House projects show that better airtightness than nationally required has been achieved.

Night ventilation has been applied successfully to many passively-cooled or low-energy office buildings. This paper analyses the thermal comfort achievable in office buildings in Spain according to European standard EN 15251:2007. Furthermore, the comfort level is evaluated using the Degree Hours (DH) criteria and the maximum indoor temperature.

Non-invasive, scalable, building retrofit solutions are very attractive deep renovation techniques to improve energy efficiency in existing buildings; this includes natural ventilation for cooling due to the low impact nature of the installation. However, a number of criteria that are important to natural ventilative cooling strategies can be substantially altered as a result of an external retrofit solution.

As a novel air distribution system, diffuse ceiling ventilation combines the suspended acoustic ceiling with ventilation supply. Due to the low-impulse supply from the large ceiling area, the system does not generate draught when supplying cold air. However, heat sources play an important role on thermal comfort in the occupant zone. Another characteristic of this system is its lower pressure drop compared with conventional ventilation systems, which reduces the noise problem and, at the same time, the energy consumption of the fan can be reduced.

Owing to the growing concern about indoor air quality (IAQ) globally in hospitals, especially after the recent outbreak of diseases like severe acute respiratory syndrome (SARS), Swine Flu (H1N1) and other airborne infections such as Tuberculosis, the quest for energy efficient ventilation system is growing. To provide acceptable indoor air quality that is capable of removing indoor air contaminants in hospital wards, sustainable ventilation strategy is required.

There is a growing consensus that the climate is changing faster than at any time in the past millennium. This is likely to have major effects upon many aspects of the built environment. UK Climate Impact Projections 09 indicate significant increases in Summer Mean Temperatures. This may suggest a requirement for cooler buildings during the summer months. In consequence, that would likely lead to an increase in demand for mechanical ventilation and comfort cooling.

In Japan, wooden detached residential houses are common; the wood components within a wall may undergo decay because of condensation in the wall or flushing defects, which can be a concern. The temperature distribution throughout the house, such as a high temperature in the attic space, can cause discomfort to the occupants. A double-skin system of room-side air gaps is considered to be an effective technique to handle these problems.

The effect of a new passive cooling device to the indoor air is analyzed based both to experimental and simulating results. The tested device is a ventilated pond protected with an aluminum layer, placed on the roof of the examined building. The indoor air temperature of the building has been recorded, before and after the placement of the roof cooling technique. The record indoor air temperature is analyzed, in regard to the ambient conditions.

Climate change phenomena such as global warming and urban heat island effects cause serious problems for the development of building technology. Therefore, it is imperative that architects and designers consider the effects of climate change on long-term building performance. At present, energy simulations are often used to evaluate the indoor thermal environment and energy consumption of buildings. In these simulations, it is common to use regional weather data that are usually based on current or past weather conditions.

Future climate change might have a tremendous impact on energy use, ventilative cooling strategies and thermal comfort in buildings, since these parameters are strongly correlated with the external weather conditions.
This paper will present results of a study of the impact future climate change scenarios as developed by the Intergovermental Panel on Climate Change (IPPC) and implemented in weather files for specific future time slices (2020, 2050 and 2080) on the design of the external envelope of a hotel building in Greece. Three climatic regions of Greece are considered.