How should I drill the holes in the wall?

To drill the holes in the wall for the ducts, you should follow the steps outlined in section "Installation arrangement" of the manual on page 18. First, position the paper template and mark the positions of the holes for the ducts. Then, use a drill to make a pilot hole and a core drill to drill the through hole into the wall. Keep a downward inclination toward the external side. The maximum length of the holes is 1 meter.