forced air VS natural air(cold wall) refrigerator?

hi pal
what are the different between forced air and natural air(cold wall) refrigerator and freezer
what are the advantage and the disadvantage of each type
and what about changing the forced air cabinet into natural air cold wall??

Cycle defrost fridge/ freezer is slower to cool but only needs a thermostat on the evaporator plate to work.

A "Frost Free" uses a portion of the freezer air to cool the fridge. (In most models.)
Frost Free cabinets have Printed circuit boards to run the various tasks. Defrost heater, defrost termination sensor, freezer temp sensor, variable drive compressor, variable drive evap fan motor, evap fan delay, open door alarm, motor driven fridge air damper, fridge sensor, air distribution motor.......and they cost more to run and repair.:(

Waiting on someone to bring out a domestic with legs so it can go and do the shopping.:p

Large difference in local humidity effects. Forced air side by side and over and under orientation per Mike chill cooler side with air supply/return from freezer side. That air tends to be at very low humidity Circulation on chilled side is at low volume flow so localized high-low humidity. So some products on the chilled side can suffer, the humidity sensitive ones like lettuce and grapes....and the location within the chilled box is somewhat critical.

Also forced draft does nothing if the fan quits and very little if you put a pizza box, for instance, in the wrong place....

Natural draft a little more flexible in that regard and can be designed with (2) evap envelopes: one services the freezer, one services the chilled section; one compressor. This requires a split binary refrigerant and (I believe) only used with larger commercial style reach in units