This top spoiler also ensures that the window remains clean.When the draught in the chimney exceeds 12 Pascal, and (very)dry wood is being burned, you will be able to keep the windowclean for a considerable length of time.However, soiling can occur on the window when the fire issmothered by closing the air regulation.The flames can be regulated by inserting the side of the key intothe groove positioned on the right-hand side of the Kalfire. Usethe right side of the handle (figure 3). By moving the key to theleft, you will minimise the air supply to the top spoiler; the fire willburn more calmly (provided that the primary air valve has closedautomatically). By moving the key to the right, the air supply tothe fire will increase and the fire will burn more strongly.5.4 Using the Kalfire W with an open or closed doorThe Kalfire W can be used as an (open) fireplace or a stove (doorclosed). The main difference, is that each use has a different airrequirement. For this reason, the Kalfire W features a fresh airvalve at the rear of the appliance (patent).Advantage: The air required by the flue duct to ensure goodconstant circulation is always introduced into the fireplace orroom in the most efficient and comfortable way. When placingthe fireplace, it is always important to take heavy air users intoaccount, such as large ventilation systems and extractor hoods.These products use powerful motors to extract air, the pressuredifference built up naturally by a flue is far less.When the door is open, the heat output will fall to about 20%. Thewood consumption will increase; as air has unregulated access tothe wood. The advantage is a cosy hearth fire.• Never leave an open fire burn without supervision; anysparks could cause a fire.• Open the damper (if present) completely.• Only use the Kalfire W as an open fireplace if there isenough draught in the flue.• Preferably use the fireplace with a closed door. This isbetter for the environment and the heat output.Closed doorOpen (fireplace) door33