Product review (1 stars): The flaps at the bottom of the exterior exhaust motor ...
The flaps at the bottom of the exterior exhaust motor do not close properly.  This creates an updraft of cold air from the outside blowing into my kitchen.  To prove my point, I shot a video of the cold air blowing a Kleenex tissue into the air. The installer replaced the exterior exhaust motor.  This did not correct the problem. Our old Thermador downdraft was well built and lasted for twenty years.  Our new Theramador downdraft (and updraft when it is off) is badly designed and cheaply made.  After one year I am ready to send it to our local recycler.