Hey guys! I work out of a converted mansion's/camp's large dining room as our theater. (www.campkiwanee.com) there is a full sprinkler system in the venue and we have always shyed away from using fog machines becuase of this. Unfortunatly dry ice is much to loud for such a close audience to bear. any ideas on alternatives, or even ways to quiet the dry ice, or any chemicals that might be of use that are known not to interefere with sprinkler sysems? Thanks!!

Dan is correct!
There are generally two types of fire suppression systems in common use.
The Sprinkler is activated by heat/temperature, while the  Deluge systems can either be by an action of heat or smoke detection &/or manually operated.
As suggested check out the fire system to determine what type it is. This can easily be done by viewing the fire maintenance Log book or inspection of the fire control panel, if there is one.
Another way is visually inspecting the sprinkler head valves, if you can see a visible glass bulb filled with coloured fluid, it’s a sprinkler. If it is a just a series of nozzles with no coloured bulb, you can bet it is a Deluge system.
The system to worry about is the deluge & the type of detectors used. Invariably if detectors are employed there will be a Fire Indicator Panel which the system is activated from. If so the actual area zone can & should be able to be isolated individually easily. You may need the Camp administrator/caretaker to instruct you on the correct procedure, as the local Fire Brigade or Authority may monitor with a Direct Brigade Alarm [DBA] on the condition of the alarm system. So they need to be informed of any alarm isolation on the premises.
Or the local Fire Station in the area, will be able to advise you on what type of system it is & of any procedures required to isolate.  
The fire sprinkler system is controlled by each of the sprinkler heads, which have a glass bulb filled with coloured fluid in each. The particular colour of the fluid determines the temperature required to be reached, before the expansion of the fluid breaks the glass & activates the system. {thus releasing the low pressure water in the sprinkler pipe & activating the hydrants ‘Clacker ‘ valve. this allows the mains pressure water to flow.}    
Temperature  & Colour of liquid inside bulb
°C     °F
57     135     Orange
68     155     Red
79     174     Yellow
93     200     Green
141     286     Blue
182     360     Mauve
227  440  Black
260     500     Black
Of course there are hybrids of these systems individually engineered to suit the situation.
So it would be in your interest to find out more information, before you use any type of smoke/fog effect. [Duty of care].