Welding Smoke and Sacramental Incense
Welding Smoke and Sacramental Incense
(OP)
I've had this posed to me half a dozen times in the past two months.
"Need a sensor to sense welding smoke to activate / deactivate exhaust fans"
"Need a sensor to sense incense smoke to activate / deactivate exhaust fans"
These things generally happen in large-volume rooms like an auto shop or church, so the smoke dissipates to a very low level by the time it rises to a place in which a sensor could be mounted.
I have suggested field trial-and-error with a VOC (volatile organic compound) sensor and/or a smoke detector with relay output like we use in ducts. I figured smoke is smoke, so a smoke detector might work if it is sensitive enough. But if not, perhaps a VOC sensor can grab the non-solid products of combustion or smoldering.
Fan needs to run a good bit after the welding / church service is over to clear it out. The time it takes to do so is in question.
Anybody have any better ideas?
"Need a sensor to sense welding smoke to activate / deactivate exhaust fans"
"Need a sensor to sense incense smoke to activate / deactivate exhaust fans"
These things generally happen in large-volume rooms like an auto shop or church, so the smoke dissipates to a very low level by the time it rises to a place in which a sensor could be mounted.
I have suggested field trial-and-error with a VOC (volatile organic compound) sensor and/or a smoke detector with relay output like we use in ducts. I figured smoke is smoke, so a smoke detector might work if it is sensitive enough. But if not, perhaps a VOC sensor can grab the non-solid products of combustion or smoldering.
Fan needs to run a good bit after the welding / church service is over to clear it out. The time it takes to do so is in question.
Anybody have any better ideas?
Best to you,
Goober Dave
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RE: Welding Smoke and Sacramental Incense
B.E.
You are judged not by what you know, but by what you can do.
RE: Welding Smoke and Sacramental Incense
Do not encourage such lazy behavior.It will take a while for the smoke to build up and reach a level that can be measured given the rather small generation rate and the large volume of the space.Any sensor will lose its sensitivity unless tested and maintained regularly and this would mean fan start getting delayed as time goes on .I do not have any faith in such lazy mob maintaining the sensor in good condition.
A welder is undertaking a dangerous task and turning the exhaust on should be part of the precautionary checks before he energises the rod.As for the church situation,I would try to locate the relief air grille over where the incense will be burnt.
If I really had to automate the fan start ,I would not trust anything other than an aspirating system like the VESDA.
RE: Welding Smoke and Sacramental Incense
RE: Welding Smoke and Sacramental Incense
RE: Welding Smoke and Sacramental Incense
I agree with all of your comments, I'll be taking a different approach when this comes up again, as I'm sure it will. Sometimes building automation goes too far.
chicopee, in the Catholic church, the smoke is a symbol of purification and sanctification. It's just a symbolic ritual nowadays, but it used to be thought to chase away the evil spirits and demons. That's what I was taught anyways.
Best to you,
Goober Dave
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RE: Welding Smoke and Sacramental Incense
if target is to reduce energy consumption, the best path would be to localize exhaust as much as possible.
RE: Welding Smoke and Sacramental Incense
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RE: Welding Smoke and Sacramental Incense
RE: Welding Smoke and Sacramental Incense
THe latest client says the welding guys always turn on the fan, but they leave it on all day. They want to minimize ventilation for energy savings. They're going to put a delay-off timer on the fan and make the welders start the timer with a pushbutton as they quit welding for the day. He says it'll be a discipline thing, and they'll adjust the timer to a value that clears out all the smoke.
Best to you,
Goober Dave
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RE: Welding Smoke and Sacramental Incense
Why don't you just stick in a relay for the fan, with a post weld delay timer . Set it to go on when the weld contactor is activated.
I know you cannot do that with a stick welder, but very few shops use stick these days. Of course having said that, yours will be one of the few shops that do.
B.E.
You are judged not by what you know, but by what you can do.
RE: Welding Smoke and Sacramental Incense
What about a welding flame detector (aka light sensor,PE cell)to activate the fan?Coupled with a delay timer might do the job.
RE: Welding Smoke and Sacramental Incense
berkshire has the method they're going to employ on this one.
For the church incense, perhaps the same thing. They just want to clear out the smoke after the mass or other ceremony, but not leave the fan on all day (or all week).
Best to you,
Goober Dave
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RE: Welding Smoke and Sacramental Incense
Dave, it sounds like your church could just use a rotary timer switch, of the type where you just set the desired run time.
B.E.
You are judged not by what you know, but by what you can do.
RE: Welding Smoke and Sacramental Incense
A twist timer (or electronic equivalent) will do fine since the church services are generally of a known length of time.
The welders are a different bunch -- they may smoke for 2 hours or 8 hours, we never know.
Best to you,
Goober Dave
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RE: Welding Smoke and Sacramental Incense
Neither of these functions needs to be automated.