A spray booth is quite simply a pressure controlled environment which is used to spray paint vehicles in a bodyshop, anything from a family car through to a fighter jet has been sprayed in a spray booth. To ensure the ideal spray booth working conditions which are temperature, air flow and humidity, the environment is equipped with extremely efficient ventilation, made up of at least one or more motors and a couple of burners to heat the air that is blown through.
One of the most fundamental components of the Booth is a good supply of air. Paint Booths require a fair amount of air to be pumped in so as to have a good air supply through the booth. The National Fire Protection Association requires a minimum of 100 feet per minute of air flow past the operator of the spray booth. For the majority of spray booths this essentially means you require a volume source of air somewhere in the region of 8,000 to 10,000 cubic feet of airflow per minute which is typically more air than most buildings can naturally supply.
Paint booths need air to be flowing through in the style of a river and as most buildings cannot provide this flow of air, an air replacement unit is often required for the spray booth. If the booth doesn't get the required level of airflow then the paint can't be whisked away and the operator finds himself standing in a cloud of overspray which eventually settles and leads to a dusty and dirty spray booth.
The filter within a booth is probably the single most important part of the setup and will have been designed to do two important jobs. To be effective the filter must be able to both capture and hold any overspray, if it fails to do this or isn't effective in doing this then the overspray can pass into the exhaust and fan stack being pushed out into the air outside. This often tends to lead to neighbours being very unhappy at the belongings being covered in paint spray particles.
It is advisable to avoid cheaper filters or fit a filter that doesn't fit properly within its frame as the overspray will not be captured properly and will lead to a build up in the exhaust and on the fan stack, this is a potential fire hazard due to a phenomenon called composting.
The exhaust is the third and final important part of the spray booth setup. The National Fire Protection Association requires a sturdy steel exhaust chamber with steel filter holding frames as a bare minimum. The size of the exhaust fan which is measured in CFM, is determined by the air required to produce 100 FPM air flow throughout the booth. The CFM measure gives the size of the fan required for a balanced operation of the booth.
It is advisable to have the fan mounted high in the exhaust stack and not directly against the exhaust chamber, doing this allows for quieter operation of the fan.
