Recently one fine Saturday I thought of cleaning one of own AH-XP18MVs ODU unit. The ODU unit pictured below is situated on my verandah, so it was easy. Though the primary reason was to clean the ODU internals, I was quite excited to have a sneak peek inside it and discover something yet unknown.
After opening the ODU fan grill (held together with four clamps and two screws) the first thing that came to my mind is how big the all-aluminum micro-channel condenser actually is. It is of more or less same height of the ODU and takes up the entire back portion and then curves to the left of the ODU where it ends. I used a new paint brush to gently brush out the dust accumulated in the condenser and it took me few minutes.
ODU Unit with Fan Grill removed
The next thing I noticed is the unique fan blade. Sharp uses different type of fan blades for their 1.5 ton & 2.0 ton Inverter category as the 18MV & 24MV are having micro-channel condensers which requires a different design in their fan bade. It has only three fins (I have seen many with four) but these three blades are huge, having huge surface area and seems to contain flawlessly smoothened curves at its edges. Sharp claims these fan blades are made with design consideration as perfected by NASA which I initially doubted, but after a closer look it seems to be very scientifically & aerodynamically designed to provide high flow velocity with minimal torque required by the motor. The fan blade seems to be made from some kind of all-weather hard plastic while being feather light which also puts less strain on the motor and saves energy.
The entire fan blade and motor assembly is mounted to an aluminum ladder type frame
Unquie desgn of the Fan Blades
The fan motor seems to be made in Japan. At least the initials on the DC motor seem to be Japanese but I could be wrong as they may be Chinese too. Please correct me if I am wrong!!! The shell of the DC motor is all-plastic and seems small for a fan blade of this size. The entire fan blade and motor assembly is mounted to an aluminum ladder type frame and mounted centrally in front of the condenser.
ODU Fan DC Motor
Japanese encryption it seems!!!
Next thing to discover was the Digital Micro-computer Module i.e the brain of the Inverter AC which is situated on the upper right corner of the ODU and above the compressor chamber. Though the circuit boards and its components are sealed inside a box to avoid dust, one can see the protruding heatsink fins (all six of them) having different height to get maximum air flow from the fan relative to its position. Quite a clever heatsink fin design. There are many heat sensors on different locations of the condenser that I can visually locate which constantly monitors and sends the information to the micro-computer.
The heatsink of the Micro-Computer Module
The entire compressor chamber is much smaller than what I thought it to be for a 1.5 tonner. It is completely insulated with an acoustic jacket to eliminate noise. No wonder why my 18MVs are so quit. Unfortunately with the tightly packaged compressor section and its complete insulation stopped me to have a look at the compressor itself and its make. Though I am informed the 18MVs have MHI compressor which are the best there is.
The entire compressor and its ancillaries tightly packaged in an acoustic chamber
Finally I find the entire ODU to be very well built, no rough edges where every component is rightly placed to its allocated position to perform its job. It even have fine touches like a thick plastic cover to protect the copper valves where the pipes get connected to the ODU (sadly absent on the India made ODUs), In other words a very well engineered product.
After Cleaning
Hope my AH-XP18MVs last for ages.
