Pro-Leaf CO2 GeneratorsPro Leaf CO2 Generators Enrich areas of up to 220m2 with CO2 grab a Pro Leaf CO2 Generator. It burns liquid propane gas (LPG) to produce CO2 + water vapour. They're super flexible you can modify your CO2 output with ease. To do this, you simply cap off burners (4kW model) or use the handy selector switches (10kW). Each unit is complete with an electronic solenoid assembly you can turn off CO2 generation at set times (with no gas leaks!). 4kW: 90m2