English

This paper examines the contribution that energy efficiency in residential buildings can make towards meeting the UK government' s commitment to reduce the country's C02 emissions by 20% relative to 1990 levels by the year 2010. It is based on work carried out by the authors and their colleagues, funded by the UK Electricity Association. Following a bottom-up modelling approach, the technological options available for use in residential buildings in the UK have been assessed.

This paper presents a set of detailed experimental data of room airflow with displacement ventilation. These data were obtained from a new environmental test facility. The measurements were conducted for three typical room configurations: a small office, a large office with partitions, and a classroom. The distributions of air velocity, air velocity fluctuation, and air temperature were measured by omnidirectional hotsphere anemometers, and contaminant concentrations were measured by tracer gas at 54 points in the rooms. Smoke was used to observe airflow.

This paper describes a methodology for simulating the transport of smoke and hot gases in buildings. The approach is based on the use of efficient CFD techniques and high performance computers to solve a form of the Navier-Stokes equations specialized to the smoke movement problem. The fire is prescribed in a manner consistent with a mixture fraction based approach to combustion, but the combustion phenomena themselves are not simulated. The mixing and transport of smoke and hot gases are calculated directly from an approximate form of the Navier-Stokes equations.

As thermal storage media, phase-change materials (PCMs) such as paraffin1 eutectic salts; etc. offer an order-of-magnitude increase in thermal storage capacity, and their discharge is almost isothermal. By embedding PCMs in gypsum board, plaster, or other wall -covering materials, the building structure acquires latent storage properties. Structural elements containing PCMs can store large amounts of energy while maintaining the indoor temperature within a relatively narrow range.

Displacement ventilation may provide better indoor air quality than mixing ventilation. Proper design of displacement ventilation requires information concerning the air temperature difference between the head and foot level of a sedentary person and the ventilation effectiveness at the breathing level. This paper presents models to predict the air temperature difference and the ventilation effectiveness, based on a database of 56 cases with displacement ventilation. The database was generated by using a validated CFD program and covers four different types of U.S.

The Environmental Protection Agency's (EPA) ENERGY STAR® Homes program seeks to reduce greenhouse gas emissions by encouraging U.S. production home builders to voluntarily improve the thermal quality of their construction by minimizing infiltration, improving insulation, and right-sizing HV AC equipment. Tight homes need active ventilation to maintain indoor air quality, but mechanical ventilation increases initial home cost as well as operating costs.

Conventional evaporative coolers are high-pressure high-volume devices that deliver cool air by water evaporation wetted pads. Natural down-draft evaporative coolers, or "Cool Towers", are devices developed at The University of Arizona's Environmental Research Laboratory. Similar to conventional coolers, these devices are equipped with wetted pads and sprays at the top which provide cool air by evaporation but the air is moved by gravity flow saving the energy required by the blower. In arid regions, cool towers are useful for cooling buildings and outdoor private and public areas.

In 1997 the State of Wisconsin began searching for low-income programs that were innovative in their approach and which offered the potential to improve or expand program delivery. TecMRKT Works responded to this call with an RFP to implement the first shared-savings pilot weatherization program in the United States. This paper describes the program being tested in Wisconsin and presents some of the early "lessons learned".

Simulation analysis suggests that electricity consumption can be reduced up to 40% in existing Florida homes. To test this theory, an all-electric home was located in Miami, Florida upon which to perform a variety of retrofits. The total annual electricity consumption in the one year base-line period preceding the study was 20,733 kWh. Detailed instrumentation and metering equipment was installed in May of 1 995 so that each energy end-use could be evaluated.