Aguide listof

Aguide listof tests to perform mightinclude the following: •What are the symptoms? The study should specify the type of discomfort experienced by occupants,such temperature,dust,smells etc.Their reactions require analysis to identify the cause ofdiscomfort. •Where and when does the problem occur? The frequency of problem needs to be identified,intermittentor constant,to detectthe contamination source. •How is the building maintained? •How is air distribution managed? Is itefficientand with sufficientair replacement? • Are the air handling units working correctly? Equipment needs to be inspected to determine if batteries, filters and humidity systems work correctly and are properly maintained. Excessive humidity is especially relevant. •Is supply air properly filtered? Are fans positioned correctly? •Are there any irregular indoor contamination sources? • Is building use consistent with that intend in the initial design? It is important to check that decoration materials,furniture and working material (printing and copying machines for instance) arenotasourceofexcessivecontamination.
Although Indoor Air Quality issues are usually due to some of the above,contaminated ducts can also be a sourceofproblems.Thatis why the interior of the ducts has to be carefully inspected.
However,two importantpoints should be noted:
•Mould will notdevelop inside ducts unless specific conditions of dirtand humidity exist. •Adustlayer may occur on the inner surface (in contactwith airflow) of all types of ducts,including metal ones.However,if the inspection reveals the presence of more than a thin layer,itis time to clean the duct.
Personal Protection
During inspection the HVAC system should be switched off.To prevent potential exposure of the building’soccupants todirtor cleaning products,the cleaning teams have to proceed with caution (and whilstatwork,wear gloves,eye protection and masks).