As it turns cold check out your collector.

As it is turning cold we are beginning to get the usual calls.  When air is recirculated back into the shop during the winter there are challenges.  The first thing that happens is that the warm air from the building is blown outside into a cold area.  many times condensation can occur. This can cause some filtration issues.  The bigger problem is the filtration rating of the filter.  If the system was not designed to recirculate, or if it is an older system, you may not have the correct filters.   Most collectors that vent outside use a polyester filter.  They are the most prevalent in the industry filtering 99.9% of nuisance dusts over 10 micron..  For humans inside a plant this particle is larger than recommended.  Dust particles reccirced into the plan should be sub micron.  There are two common ways in practice. one is to use a secondary hepa filter, or to use a filter in the dust collector that filters finer dust.  Both have more cost involved but will prevent inhalation problems.  
For more help on this subject contact one of our knowledgeable staff members at:  816-869-3201