When conducting on-site industrial hygiene inspections of numerous art schools and university art departments, the most important factor I look at is the ventilation systems in the various studios. Too often, I find that the only ventilation systems in areas where toxic chemicals are used are the heating, ventilating, and air conditioning (HVAC) systems.
Installing proper dilution ventilation and local exhaust systems in an existing facility is several times more expensive than installing the proper ventilation when the building is first built or renovated. Therefore, for both the initial planning or renovation of a building, it is important to make sure that proper ventilation is mapped out and installed from the beginning. Unfortunately, I have found new art buildings where this was not done, and ventilation systems had to be rebuilt at great cost. HVAC vs Industrial Ventilation
In planning a new art building, you must know the difference between HVAC systems and industrial ventilation. Unfortunately, HVAC systems are not designed to exhaust toxic chemicals, and can, in fact, create hazards by distributing the chemical gases and vapors throughout the building. In addition, HVAC systems commonly recirculate most of the air to save energy by not having to heat or cool outside air (called makeup air) used to replace exhausted air. Unfortunately, recirculating air also results in the recirculation of any toxic contaminants in the air. It is fair to say that in art studios where toxic airborne chemicals are being generated, energy conservation and occupant health are in direct conflict with each other.
Often, extensive recirculation has resulted in health problems in buildings which are not producing toxic contaminants. This is referred to as Tight Building Syndrome. Industrial ventilation, on the other hand, generally relies on exhausting contaminated air to the outside and not recirculating it. There are two types of industrial ventilation: dilution and local exhaust ventilation. Dilution ventilation involves bringing in clean makeup air to dilute the contaminants in the air to a safe level, then exhausting this contaminated air to the outside with an exhaust fan or ducted system. Dilution ventilation does not eliminate exposure but lowers it. Local exhaust ventilation, on the other hand, captures the contaminants at their source and exhausts them to the outside before the contaminants get into the room air that is breathed. Spray booths and enclosed laboratory hoods are two common examples of local exhaust ventilation. With particulate-collecting systems, the exhaust air can be recirculated after being filtered if no other contaminants are present in the exhausted air.
Choosing a Ventilation Engineer
For a new art building, choose an architect who has experience designing art buildings. Similarly, when designing a ventilation system for an art school, be sure that the ventilation engineer chosen by the architect has experience and training in industrial ventilation. Most mechanical engineers have only HVAC experience, and have not had training in industrial ventilation systems. For choosing ventilation engineers, here are some simple guidelines. Have they taken a course in industrial ventilation? Do they have the book Industrial Ventilation: A Manual of Recommended Practice? This book, published by the American Conference of Governmental Industrial Hygienists, is the bible of industrial ventilation. What other art schools have they designed ventilation systems for? Visit or talk to art teachers at these schools to find out if the ventilation systems work.
Planning Your Ventilation Systems
The ventilation planning should begin once it is determined what art materials, processes, and equipment are going into a particular studio. The best way to proceed is to have the architect, ventilation engineer, and school facilities planner in one room, and then bring in the various art teachers involved in a studio to discuss what actually will take place in that studio. Often, teachers do not know what type of ventilation systems are needed for their art processes, and architects and engineers do not know what chemicals are being used in a particular process, or the hazards of the materials. I have been called in as a consultant to provide an interface between these two groups and make recommendations for ventilation for the various art processes. This has been particularly effective when the mechanical engineer did not have industrial ventilation experience. In these instances, I could provide specifications for the dilution ventilation or local exhaust hood, and the mechanical engineer could design the ventilation system from that point.
Some Important Design Factors
In planning a ventilation system for a particular studio, you have to be aware of several factors: 1) what types of airborne contaminants are being produced, and how much; 2) where these contaminants are being produced; and 3) when these contaminants are being produced. You need different types of exhaust systems for different types of art materials. Dilution ventilation, for example, is not suitable for dusts and welding fumes. Local exhaust ventilation is needed. Dilution ventilation is also not recommended for large amounts of toxic gases and vapors, or for highly toxic ones, because the amount of dilution ventilation needed to dilute the gas or vapor to safe levels would be enormous.
Planning ventilation systems also depends on where art processes are occurring. With oil painting, for example, it would be impractical to put local exhaust ventilation at each easel since easels are not fixed and local exhaust systems would block the view. The solution is to provide dilution ventilation for solvent use at the easels, but require final solvent cleanup to be done at a cleanup station provided with a slot hood for local exhaust ventilation.
Another common problem is the lack of fixed work stations. When students can use solvents anywhere in a room, applying grounds and resists for the etching process in intaglio, it is very difficult to plan. It is impractical to put slot hoods at every work table where a student might use solvents, as has sometimes been requested. Instead, the intaglio studio should be planned so that solvent use is restricted to certain locations provided with local exhaust ventilation. Planning specific locations where hazardous studio processes take place will result in providing adequate ventilation without the high costs of trying to provide ventilation everywhere.
The hours of operation of a studio are also important. When the studio is not in use, there is no need to operate dilution ventilation and local exhaust systems. But if the studios are used after hours, it is essential to make sure that the exhaust and makeup air systems can also be in operation at those times. I have seen many schools where all the ventilation systems were shut down at 5 PM, even though students were working in these studios in the evenings. Further information on the types of hazards found in art processes or on ventilation can be found in the references below, or by contacting the CSA.
References 1. Clark, N., Cutter, T., and McGrane, J., Ventilation, (1984). Lyons and Burford Publishers, New York, NY. 2. Committee on Industrial Ventilation. (1992). Industrial Ventilation: A Manual of Recommended Practice. 21st ed., American Conference of Governmental Industrial Hygienists, East Lansing, MI. 3. McCann, M. (1992). Artist Beware. 2nd ed., Lyons and Burford, Publishers, New York, NY.