Low Smoke or Smokeless Flux

I'm new here and hate to bother you all, especially if this question has been asked before. The question is this, Is there any low or no smoke flux that you would care to recommend. The reason I ask is that I have COPD pretty bad and smoke is not my friend. I have tried wood pellets, paraffin, bees wax, and some stuff I bought from Brownell's a few years ago, sort of a white crystal like powder. It seems I've heard borax powder will work, but has a lot of faults. If it matters I am now using a lee 20 lb. bottom pour pot and mostly lee 6 hole molds. Any suggestions, I'd certainly appreciate. You all have a real knowledgeable forum here.

Set up a large fan down wind of your smelting but close to the pot, Problem solved!

I have a bathroom fan vent about two feet above mine. You want it high enough so that the flames from the sawdust can't get too close. I have metal tubing vent the smoke outside. Works great.

As my sawdust heats and begins to smoke, I light it, presto! no smoke. Same with waxes if I choose to use them. With your problem this plus good ventilation you might be alright. Should mention that I do leave the the door to my shop open, hot or cold, when casting and have a fan blowing about head high above my casting area. GW