I installed Vent a hood in 1986 and we have been using it since then (for 26 years). My wife cooks Indian food on an industrial scale. My kitchen ceiling is white and it is till today looks as white as it was painted 26 years ago. There is no layer of oily film to speak of. I paid $550 then for the unit with two blower (650 cfm). I have a PHD in Physices, I can tell you The Magic Lung blower system is the best design to get the maximum air flow into the blowe without any resistance. Yes, you have to clean it. You don't need to clean the squirrel cages, if they are too dirty, you can buy them for a#12/piece. They beed to be balanced just like your car tire. For your information; anything which is rotating at high speed around any axis needs to be balance to avoid vobbul and subsequent vibration. Your mechanics did not understand the fundamental . The sealed blower means you do not need to oil the motor. We remodeling our kitchen and I am going to replace my 26 years old Vent A Hood (worling perfectly) with a stainless steel chimney model. I don't think there is any hood in the market today with this kind of efficiency. My neibours say when my wife cooks, they savour the the Biryanee smell and that spicy aroma the hood sucks out, leaving no aerosol particles to lingler around to be absorbed by your clothings, hair and carpet. All my Asian and Indian friends use Vent A Hood far longr than you have. No one have evern complained about maintainance. Remember, even Toyota Camry needs regular mainainance.