NADCA Standard 1992-01 is the first standard governing air conveyance system cleaning to be finalized by the National Air Duct Cleaners Association and its Standards Committee. This Standard generally addresses the mechanical cleaning of air conveyance system components composed of non-porous materials. Standard 1992-01 is intended to provide a voluntary performance standard which cleaners and building owners may wish to consider in determining the requirements for specific cleaning projects, and which can ensure certain minimum cleaning results on particular cleaning project
In recent years, poor indoor climate has increasingly been seen as the cause of health problems for building occupants. Today, there is good evidence in some areas why such problems arise. Unhealthy substances given off by various building materials, the existence of mould and general air pollution are the main causes. In general, the most important way to remedy the problem is improved ventilation. Poor upkeep and maintenance have led to a decline in the performance of existing ventilation systems.
An effort has been made to gather the information available about duct cleaning. The emphasis in the survey was on the hygienic aspect of the cleaning of supply air ducts. Most of the literature deals with cleaning of exhaust ducts. Guidelines for the cleanness of ductsurfaces have been given by some organizations, but the scientific basis for such guidelines needs more research.