Indoor Firing Range
Indoor Firing Range
(OP)
I have the unusual task of designing an HVAC system for an indoor firing range (well unusual for me). I did a search and arabei gave seme good lead safety info but that was back in 02 and seeing if assitional input can be provided.
I researched ASHRAE, and they do not have anything in their 4 books. I did a search for it in thr ASHRAE Journals and did find an article, but it was specific to an Alaskan range. Helpful but I could use more.
It appears that the main goal is to protect from lead exposure, so I found some things on the CDC website and NIOSH guidelines, that I am looking at now.
Any suggestions would be appreciated.
I researched ASHRAE, and they do not have anything in their 4 books. I did a search for it in thr ASHRAE Journals and did find an article, but it was specific to an Alaskan range. Helpful but I could use more.
It appears that the main goal is to protect from lead exposure, so I found some things on the CDC website and NIOSH guidelines, that I am looking at now.
Any suggestions would be appreciated.





RE: Indoor Firing Range
American Air Filter (AAF) had a good basic indoor gun range design manual way back when I did my first indoor gun range. I'm sure there are updated materials on the Web by now. Basics are: laminar flow downstream(downrange) airflow with low velocity (<30fpm) air supply behind the shooting positions, use an intermediate exhaust pickup about 3-5 meters downrange of the shooting positions to capture gunsmoke, and about 2/3 to 3/4 of the main range exhaust picked up over the bullet trap. The airflow is usually based on a nominal 50fpm to 70fpm laminar downrange air velocity, so whatever the range "face area" is, that will determine minimum range airflow.
So say you have a range that has a width of 50 feet, a room height of 9 feet, then your minimum airflow will be [(50x9) x 50fpm] = 22,500 cfm. The air may be a mix of recirculated air (check filter requirements and NIOSH/OSHA regs) or 100% outdoor air with no recirc, in which case you'd want to use a heat/energy recovery ventilator for sure.
RE: Indoor Firing Range
I have done some research and your "Basics" are right on.
I cant find any requirement for HEPA filters, although NIOSH does recommend them. OSHA requires the working environmnet to be less than 50ug/m3, and since I am not using a recirculation system, I should be covered. The EPA does not require HEPA filters, but does require the lead exposure rate of the exhaust air be less than 1.5ug/m3. So if I use a good bullet trap, hopefully that will not require HEPA filters.
The exhaust above the trap, I was going to move the existing exhaust duct that is over the shaft to about 5 feet before the trap. My thinking is it will give the bullet fragments time to settle and fall in the trap, and not be exhausted outside, possible putting me over the EPA requirements and requiring HEPA filters.
RE: Indoor Firing Range
The roll-your-eyes part of this was the fact that the building is located on the corner of of two main roads that see a huge amount of traffic with their auto exhaust spewing out. The filtered exhaust air quality was actually better than the ambient air quality....
The bullet fragments are not the source of the airborne lead polluton in a gun range - there is molecular particulates from the gun itself, and the particulates from the bullet trap- the particulates are fine enough that they don't "settle" at the bullet trap. If a lead particle is big enough to settle out, then it's not part of the airborne particulates.