Ventilation systems for residential buildings can be generally categorized as supply, exhaust, or balanced systems. Subcategories include: integration into central air distribution ducts, or single- or multipoint air distribution; This effort focused on establishing a design methodology for central-fan-integrated supply ventilation systems using an outside air duct to the return side of a central air distribution fan, with a specialized fan recycling control.

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.

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.

While there is no convincing technical basis for current code requirements for crawl space ventilation, most codes still require operable vents and the practice is well established among builders and architects . While the evidence against venting is compelling to many if not most in the research community builders and code officials apparently want to see hard evidence. In this research project I measured weekly energy consumption for space heating for a 1150 square foot home in a climate with 5900 heating degree days.

Natural ventilation in office buildings can sometimes offer other advantages than traditionalmechanical ventilation systems. Often natural ventilation systems are promoted at an earlystage by an architect, but perceived dificulties, e.g. to pre-determine the function of a naturalventilation system, can serve as a barrier and a mechanical system is often chosen instead.

Concentration of pollutants produced by car traffic in a street below the roof level has large spatial variations. In a street, pollutants are diluted by the turbulent air flow which is induced by the wind speed above the roof level, and also produced by car displacement. The airflow structure is in relation with street size and building shape. Particularly strong gradients of concentrations can be observed vertically and also horizontally in front and along buildings where are set up ventilation inlets and windows.

The principles of a new tracer gas technique is described in the paper. The new technique involves pulse injection of tracer gas and has the same advantages as the previously known homogeneous emission technique. It can for example advantageously be used in large buildings and buildings with many rooms and yields information on the distribution of ventilation air within the building. However, contrary to the homogeneous emission technique, yielding the average ventilation performance during an extended time, the new technique allows measurement during short term periods.

Pre-assessing the reliability of ventilation systems is a dificult task and no simple methodshave existed. This paper presents a tool for estimating the reliability of domestic ventilationsystems. In general, ventilation reliability means the probability that the chosen ventilationsystem performs in an acceptable way for a certain building, in a certain climate, betweenscheduled maintenance measures.