https://imagetolink.com/ib/cu725NLRK1
https://imagetolink.com/ib/nJcRD2l5fx
taller shelf with shorter tube.
also that tube is not ideal if it has no insulation.
https://www.homedepot.com/p/Master-Flow-8-in-x-25-ft-Insulated-Flexible-Duct-R8-Silver-Jacket-F8IFD8X300/202562741
the home depot will keep the heat in the tube.
I would want the miner to be on a five or six foot shelf right
under the window. and the tube could be six feet long out the window.
I would also use two or three feet of tube on the intake.
even if the same shelf is used bring in right under the window to shorten the exhaust .