Q:I saw your video and web page directions on horizontal chimney option using a 90 degree elbow and extra chimney sections. Do you have to use extra chimney sections if you use 2 – 45-degree elbows to clear the window?
A:The draught resistance created by using two 45-degree bends is less than that of two 90-degree bends; therefore, this is a better option for cleaning windows. However, it is usually still necessary to add an extra vertical flue section to compensate for the horizontal offset and maintain good draught.
Whether an additional pipe section needs to be added depends on your total vertical height and how high above the tent or roof the chimney outlet is situated. Generally speaking, the length of the horizontal section should be kept as short as possible, and sufficient vertical pipework should be added to ensure the outlet is well above the roofline.