cooling

We present a simple model to calculate the energy loss by free cooling at night. The time dependence of the exhaust air and wall surface temperatures is predicted by a simplified dynamic model that couples air flow, heat transfer, and wall temperature. For given ventilation rate the model predicts that the total heat extracted from the building during the night can be maximized by increasing the heat exchanging surface area and the thermal effusivity, of the wall materials. The influence of ventilation rate on the heat removed by freecooling at night is discussed.

Night cooling is a viable technique in the UK, but there is no suitable commercially available equipment. The BRE has been testing prototype ventilators and concludes that they work although weather, security and acoustics issues need to be addressed.        

How do tenants of public housing respond to retrofits to improve their comfort and energy use during the cooling season? In contrast to retrofits to improve heating or lighting, cooling retrofits have been little studied, despite extensive programs by utilities and housing authorities to reduce this end use. A local utility and a housing authority have been retrofitting their buildings with evaporative coolers, ground-source heatpumps and other cooling measures.

This paper examines key issues involved in evaluating benefits of tree planting programs from the perspective of electric utilities, as well as from a wider perspective of public and private entities that may benefit from such programs. The nation's largest shade tree program, sponsored by the Sacramento Municipal Utility District (SMUD) in collaboration with the Sacramento Tree Foundation (STF), is used as a case study.

Interest in the UK regarding the design of passively ventilated and cooled buildings has resulted in much work on the thermal performance and likely environmental impact of such buildings. Little work assessing the impact of the passive design approach on the construction process has been undertaken. This issue is examined herein, through the initial development of a methodology quantifying the relationship between passive environmental control (PEC) and the construction process, leading to a means of classifying buildings according to their prefabrication strategy.

Since the combustion of fossil fuels is the leading causative factor in global climate change, the "Westernmodel'' of adopting energy-using technologies and using ever-greater amounts of energy will have important consequences for the future of human life on the planet if it is transferred on a wholesale basis to the developing world. It is thus important to Uy to understand, in the context of global development.

The use of computers for simulating building thermal behavior started early at the Royal Institute of Technology in Stockholm, Sweden. The first example of such use dates from a 1957 study of an exterior wall exposed to solar radiation. The simulation program, later named BRIS, has gradually evolved with regard to the users and growing computer capacity. It has been used since the early sixties for research projects, design work and development of new systems, among others the ventilated hollow-core slab (Thermodeck) system.

As an introductory note, this aims to place the need for cooling for thermal comfort into the context of overall energy efficient building design. Additionally, it stresses the role of ventilation in meeting cooling requirements. Chapters are included on ventilation and cooling requirements; factors affecting cooling load; ventilation and cooling systems; and energy issues in ventilation and cooling, covering space cooling load, plant load and fan energy.