Do I need to clean coils in haier hwro6xc7 air conditioner

You always need to keep both coils clean on your AC.

The evaporator coil (where room air is drawn in and through a filter) - is easy to keep clean - 'just keep the filter changed on a regular basis and you will probably never need to actually clean the evaporator coil. Occasionaly you might need to brush the coil with a brush or something - but this is not a big concern.

The condenser coil (where hot air blows from) is even 'easier,' for you don't have to mess with a filter, just keep the coil clean. You can occasionally pull the unit (when needed) and wash this coil with a water hose. In reality this coil will not get very dirty very fast - although it will (over time) acquire some dirt/dust, but as I say - it is pretty easy to keep clean. Note: Condensing units (split systems) that sit in a yard will get much dirtier much faster than window/thru the wall units such as yours, but you still have to keep a eye on the coil.

A good rule of thumb - is to change the filter (in front of the evaporator coil) - monthly.

As for the condenser coil (where hot air blows from) you can easy see it and just need to keep it clean, with no set (usually) time to do so.

good luck!