passive cooling

It is only comparatively recently, since the development of mechanical ventilation and refrigeration, that it has become possible to completely control the air quality and thermal environment inside buildings, irrespective of outdoor conditions. However, such control is an energy intensive process that requires reliable energy supply. Concerns about future security of conventional supply, combined with the impact of fossil fuel emissions on global warming, has resulted in renewed emphasis on building energy efficiency.

Vegetation on the building envelope can have a marked effect on the microclimate and on the building’s energy behavior as well. In this paper, the impact of planted roofs on the thermal load of buildings is presented. Based on measurements and a series of

Recent studies predict a dramatic increase of cooling energy demand in Europe, despite the availableknowledge and technologies of passive cooling. The international project KeepCool addressed thisgap, searching for intelligent ways to promote the market penetration of passive cooling technologiesand a new definition of sustainable summer comfort based on the adaptive comfort model. The projecttailored the available information into a toolkit for building owners, planners and building users.

This paper aims to report the solar and thermal data for various common and innovative materialsused in outdoor urban applications. The tested materials include various types of coatings, tiles andasphalt pavement. In the framework of this research, the spectral reflectance and the emissivity of thematerials were measured using a UV/VIS/NIR spectrophotometer fitted with an integrating sphere andan emissometer. The solar reflectance of the samples was calculated.

The potential for passive cooling of roof slabs incorporating an air cavity is important with respect tothermal comfort. Roof systems in traditional buildings, incorporated a ventilated roof or an air cavity.The concept has been proposed again in contemporary buildings in the construction of roof slabs,using a modular formwork system, where the cast in situ concrete slab is isolated from the screed with the introduction of a ventilated air space. The cavity is primarily intended to curtail the conduction and inward radiation of heat from the intense solar insolation on the concrete roof.

In this article the concept of a new energy-efficient office building and results of a 3-year monitoringare described. The monitoring was performed within the German funding programme ENOB.In this building most of the offices are naturally ventilated and passively cooled. Another focus of theenergy concept is on regenerative heating.Monitoring results show that the integrated planning enabled a very low consumption of energy forheating, ventilation, cooling and lighting.

The objective of this paper is to present long time monitoring and post occupancy evaluation of theMoravian Metropolitan Library with the ventilated solar faade used for space heating and with mixing chamber for cooling with the forced ventilation. In consequences of new requirements from the EU Energy Performance of Building Directives 2002/91/EC and changing Czech building regulations is necessary support collective research effort on quality assurance and standardization on solar components and installations in buildings.

To gain access to information on energy use in office buildings, the German Federal Ministry forEconomy launched an intensive research and demonstration programme in 1995. In advance of theEU energy performance directive a limited primary energy coefficient of about 100 kWh m-2a-1 as agoal for the complete building services technology was postulated (HVAC + lighting) for alldemonstration buildings. A further condition was that active cooling be avoided.

For that study, 12 office rooms of a "Solar Optimised Building" in Germany have been monitored. The data have been evaluated by a new method for analysis that deals with short and long term measurements and with building simulation. A comparison between monitored data and simulation of a building with passive cooling by night ventilation is made on a long period.

The aim of that study is to establish characteristic building parameters and to analyse the night ventilation effect with these parameters. Measurements were made thanks to a parametric model and a building simulation programme.