Hi,I see that you are recommending normal fans instead of heat-proof ones — does this also work for big torches (I’m getting a 50mm Zenit burner in 2 weeks)?
If I buy a normal fan, what do I need to look out for — because if the air is cool enough for a normal fan to handle, are plastic blades ok?
Do I need to make the vent to the fan longer to compensate for the temps, and if so, how long?
I’d love to see a public post about this, I’m sure other people are also wondering about this, and the price difference between a heatproof fan and a normal one is huge in Europe, the fan can easily cost me more than the torch did!
thanks for the blog,
Heat is not “typically” an issue, however, with larger torches and “larger/longer” flames, heat can become an issue. The reason heat isn’t usually an issue is because of dilution — we are moving a lot of air through the system per minute, upwards of 800 CFM. Any heat that is generated inside the work area is going to get diluted by that large air flow. However, a large enough torch is going to generate enough heat to overcome that dilution, and that is something you have to watch for.
This is one reason why I recommend the squirrel cage type fans — it keeps the motor out of the air flow, and somewhat isolates the motor from picking up heat through conduction. The further the fan is away from the hood also tends to isolate the motor — the ducting will warm up, and the air will cool down to a certain extent.
I do not suggest ever using a fan that has plastic fan blades. That is a recipie for disaster.