TN 18/92

This technical note aims to bridge various disciplines by reviewing published literature on the hygiene of ventilation systems. It provides designers with information to limit contamination, as well as aiding building owners in procedures to help mitigate the effects on the occupants of a building. Ventilation systems are often outside an employers' interest, and there is a perceived conflict of interest between occupational health and production. It is only when the workforce bring problems to their attention is any interest shown in the condition of the system. The hygiene of air conditioning and ventilation systems has frequently been neglected by building owners, largely as a result of long lengths of inaccessible ductwork being "out of sight and out of mind". Today, many buildings are refurbished, and where the air conditioning system is largely unaltered, duct cleaning is an important item often omitted in the refurbishment. Additionally, little is known about contaminants accumulating in ducts and their effect on indoor air quality, hence no firm guidelines have been established for procedures to inspect, maintain and clean these systems.
The adverse publicity, absenteeism and reduced productivity associated with "the sick building syndrome" has put the spotlight on improving indoor air quality. It is almost certain that progressive litigation will ensure guidelines are established for keeping ventilation systems clean, to maintain a high level of air quality for the health and efficiency of occupants. Engineers do not generally have knowledge of such factors as microbiological contaminants and methods for their control. Also, knowledge gained from the study of microbiology has not been sufficiently available to engineers to apply in practical use. This report aims to remedy these shortcomings.


Designing against Terrorism

by Stephen Loyd and R. Bunn

Published 21 March 2002
This illustrated publication offers a compendium of articles covering the effects of explosive devices on buildings, and ways to mitigate those effects. Produced in collaboration with "Building Services Journal", the magazine of the Chartered Institution of Building Services Engineers, the technical note contains articles written in the wake of the major London bombings in the 1990s, and a first hand report on the effects of blast damage on building services and the scope for refurbishing blast-damaged plant items for re-use. The guide also acknowledges the threat to building occupants from bio-terrorism, and includes a useful checklist and bibliography.

TN 6/94

Fire Dampers

by Stephen Loyd

Published June 1994
Fire protection equipment in a building will be specified for either life safety or for protection of the building and/or its contents. Air conditioning and ventilation systems are a common feature in many buildings, but where ductwork pierces a fire-resisting compartment, fire dampers should be installed to prevent the passage of heat and smoke. After a number of years remaining inactive, it is essential that fire dampers should operate correctly in the event of a fire. On one of the worst fire disasters of its kind, the MGM Grand Hotel fire in 1980, a factor was that some fire dampers were disabled and did not close when their fusible links melted. With a service life of around 20 years, regular maintenance and inspection should ensure maximum reliable service and prevent premature failure. Many manual-reset-type fire dampers are located in either difficult or inaccessible positions, and are probably never checked or maintained. Brought together here is the published guidance on selection, installation, commissioning and maintenance of fire dampers for reliable performance.

v. 13/98

Cold Water Storage Tanks

by Stephen Loyd

Published August 1998
This title states that water tanks may need to be cleaned to minimize the risk of infection from bacteria, which could be harmful to humans. Cleaning will also prolong the life of tanks and help reduce costly repairs and downtime. Tank cleaning is a specialized operation carried out with temporary equipment installations, possibly involving aggressive and toxic chemicals, using high pressures and operating in wet conditions. It reviews the techniques for cleaning water storage tanks as well as good design, installation and maintenance practice. Separate sections deal with - legislation, tank design, protection, tank location, space allowance, contamination, inspection, disinfection, records, cleaning, repairs, sampling and testing of water.