A question from a fellow grower:
could you tell me what size or type or power of extractor fan to fit inline as in attachment, please?
The tent is 120cm X 70 X 165 high. The tubing is 15ft going up to am attic and then out thru roof, with two bends.
The height is not a factor. Hot air rises. A 4" vortex fan will exhaust that space in seconds. Calculate the cubic feet of your tent. Once you have that value. Decide on a fan that will exhaust that space.
Fans exhaust in cfm, cubic feet per minute. How many cubic feet your grow space is, determines how big or how often you exhaust the heat from your grow space. 
; Determined also by humidity “RH”.
You will have to go to the hardware store to buy the ventilation adapters, to break down the tents exhaust port, to the fan port size. Fairly simple. It is all standard.