When To Change The Filter On A Fume Extractor

[SETEC_Astronomy]

I was fortunate enough to receive a fume extractor over the holidays and I can't seem to find when it's necessary to change the filter. Does a filter change depend on elapsed time, flow rate, chemical concentrations or some combination thereof?

[haklesup]

Like all air filters, some combination of air flow and how dirty that air is. Unlike water filters, time sitting around doing nothing will not degrade the filter.

Unless you're in a factory where you need to predict when and how many filters to keep in stock, I would just wait until it appears to have difficulty moving the fumes. I'd guess that's when airflow is roughly 50% of new. Depending on your usage, it could last years. These are generally designed to run all day long. If your model has a foam prefilter before the carbon part, that may be washable since common dust will be trapped too.

[SETEC_Astronomy]

Thanks for the info. I guess my concern was that the activated carbon filter could become saturated by lead and flux fumes before becoming clogged by dust. Is that unrealistic? If that is possible would the fume smoke stop "disappearing"? Is there any visual indication that the filter has become unsafe? I'm not overly concerned since I've been soldering and handling lead for over a decade without protection (which might explain a few things.... ) but I'd prefer to be in the know.