GEN-1 co2 generator. Do I need a controller? Any tips appreciated

I am looking into a propane burning co2 generator, but when I started doing research I found out that almost everyone who has one also has a controller. Is the controller necessary? In a 5x6x15 room would the GEN-1 with 4 burners be what I need, and can I get away with buying no controller? Thanks

One of the issues with CO2 burners is the heat that is generated. I use a plain ole 50lb CO2 bottle with this Digigro regulator/controller combo. The controller help keep the room at 1500ppm.

http://digigro.com/shopexd.asp?id=31


http://www.ebay.com/itm/digigro-Controller-and-Regulator-Complete-Co2-Package-/250960236375?pt=LH_DefaultDomain_0&hash=item3a6e654f57#ht_2171wt_689

What kind of heat are we talking about? I have fans and intake, exhaust in a pretty big room. There is a co2 generator for around $260 on ebay and this is what I amplanning on going with unless you tell me my room will be 100+ degrees.

I stayed away from CO2 burners because I have enough electronics putting out heat already. I wouldn't think it would be too much. But if you have your room vented to reduce heat you are pulling out the CO2 you just dumped in the room?!?

A few degrees increase in the Winter could be significant in the Summer months.