I am a fire protection engineer of 35 years. Believe me there is no such thing as "free" software for fire sprinkler hydraulics. A good software program is Hass (770) 934-8423. Simple calculations can also be done in longhand. A good book to read for simple calculations is...
I want to use the windows or crossing command to convert several hundred circles (fire sprinklers) on a drawing to individual blocks, that are all the same, so that I can use the "count" command to get an accurate count of fire sprinklers in a warehouse
