ventilation

[Joan]

Vince-I have a problem for you. My studio is in the same room as my indoor pool.
The room is 60'x26'x10' high. There are 3 8'x8'sliders and 6 other windows 2'x3'.The ventilation for the room is currently two restaurant/industrial size fans. One is in the attic and operates automatically when the humidity gets too high. The other is manually operated and I always have it running when I am working. This fan is mounted about 6' up in the center of the 26' wall. I work in one of the corners nearest the fan and am facing it. This fan exhausts all of the air in the room in 5-10 minutes. (The room is heated and if the fan is on in the winter, the room is quickly cold) I work approximately 8 hours a week for six months of the year. I am away from my studio for the other 6 months. Do you think I need additional ventilation and if so, what? Thanks Joan

[Vince]

I have no idea. Without an actual measurement of the airflow and how the combustion products circulate around your breathing zone I can't say. You may be OK or you may not. A lot depends on what happens to the torch combustion products before they are captured by the fan. If they circulate in your breathing zone before they are exhausted, you don't really have the ventilation that you need. A simple relationship between the fan capacity and the room volume for a room of that size is essentially meaningless to describe "local exhaust ventilation" which is what you need. You might simply have what is called "dilution ventilation" where you are dependent on the sheer volume of air in the room to dilute any harmful combustion products to harmless levels before the fan captures and exhausts them. As I said, a measurement is needed, and I can't do that from here.

Vince

[Joan]

Thanks Vince. Can you advise me how to obtain the necessary measurements? Yhanks Joan

[Joan]

Vince. I neglected to mention that I work on a minor and use only effetre or murano. I do use foils and enamels.

[Vince]

You would need to contact a local professional who has the requisite instrumentation to do the airflow measurements along with smoke generation means to get visual confirmation of the measured airflow. Professionals use various instruments to measure airflow direction and rates and they have a number of smoke generators available for the visual confirmation. Typically you need someone who works on industrial ventilation systems, not your local home heating and air-conditioning person.

Vince

[Joan]

Thanks Vince. I appreciate your help. I'll let you know how I make out.

[Vince]

OK, good luck with your search.

In general, it is best to capture the torch combustion products as close to their source as one can and exhaust them immediately to the outside. That's what "Local Exhaust Ventilation" (LEV) means. Having said that, there are many situations where proper airflow and/or dilution can be satisfactory solutions, especially for small torches, and in large rooms. There are limits on how well this can work and every room is a bit different. For those at the last Gathering in Portland, perhaps you will remember how quickly the demo/open torch rooms became overloaded with fumes when all the torches were going. I could remain there only a few minutes before I knew it was time to leave because of the build-up of combustion products in the room air. In the main presentation room with a single demo torch there was enough dilution and air movement that the room air remained acceptable for the bulk of the day, even though there were times when the fumes could be sensed. That's just two examples of successful and unsuccessful dilution at work.

In your situation, there is simply no way I can be more helpful unless I were actually there and could do the measurements myself, but I think we are about 3,000 miles apart so it isn't going to happen.

Vince