It sounds to me like your talking about using open fermentors in an area where you have no control over temperature. If this is right then a lot of what was previously mentioned won't help. You cant bung an open fermentor, nor can you allow the pressure to equalize in an open vessel as you will continually lose CO2. You can definately get away with open fermentation but you would need to research it first and have some kind of temperature control for the fermentation room. You would do well to purchase at least one bright tank capable of being pressurized to 15psi and with a cooling jacket so you can get the beer cold enough for packaging. That way you could open ferment and then transfer to your bright tank for conditioning and Carbonation. It may be extremely difficult to to hit target CO2 levels with no pressurized vessels. Also if you have a pressurized tank with a sample cock you could buy a Zham and Nagle CO2 tester for accurate measurements.
"You are what you is." FZ