What respirator is bearable in a hot shop?
Anything that moves air. The misery of a mask in summer is mostly rebreathing your own warm exhale behind a seal. A powered unit pushes a continuous stream of filtered air across your face, which is the same reason it does not fog.
Heat is the reason more shop respirators end up on the bench than any filtration argument. A sealed mask traps warm humid air against your skin, and in July that becomes intolerable long before the dust does.
The mechanism that helps is airflow rather than any cooling element — there is no refrigeration involved in a PAPR, and anyone implying otherwise is overselling. What you get is a continuous stream of filtered air moving across your face instead of a pocket of your own breath sitting still.
Three airflow settings — 170, 210 and 250 litres per minute — let you trade runtime for airflow on a hot day. Highest setting, shortest battery life.
If your shop is genuinely hot, do the boring thing first: move air through the room. A powered respirator makes wearing protection tolerable. It does not make a 40-degree garage pleasant.
Related questions
Do I actually need a respirator for woodworking, or is that overkill? Does the carbon pre-filter mean it handles fumes? Why do my glasses fog up under a dust mask, and what stops it? How often should a PAPR filter be changed?The Breathie Thingy
A powered air-purifying respirator for woodworkers. $499 for the first 30 units of each batch, including a spare filter kit.
See the current batch