Hello all.

That vertical standing screen prevents sparking ambers (¿is that the word?) from burns reaching wood floors, carpets...  Is there a proven 'eye' size that works best ?  Does it work as a 'spark arrester' ?

And for the heat part; can some screen 'eye' size impede the heat transmission, like a microwave oven does need to block the emission of microwaves ?  If it does impede the heat from passing trough, the screen would heat up more and release the heat into the room air, right ?

I think heat passes through a metal screen easily (metal absorbs, then re-radiates the heat and of course goes right through the small holes).  The holes would want to be fairly small, to catch any  embers that may pop out.  In my state, you can't have carpeted floor next to the hearth, generally some kind of masonry surface or surface covering is required out to a certain radius.  Might actually be in the UBC for the States.