The size of your gas appliance and the level of heat will influence the length of time you will get. We have included some examples below to help give you an idea. A 11kg patio gas cylinder will power a 13kw patio gas heater on full power for up to 11 hours. If the heater is on a reduced power you may get longer from your 11kg patio gas cylinder. A 11kg patio gas cylinder will give you up to 16 hours of cooking on a standard 3 burner barbecue (10kW) on full power. On a reduced heat setting or using a small one burner BBQ (7Kw) the 11kg patio gas cylinder can give you up to 22 hours cooking time.