Central Aircon: FAQ
https://emiliowpvv.bloggersdelight.dk/2021/03/29/seven-key-rules-to-save-money-on-cooling-this-summer-season/
Central air conditioning conditioners flow cool air through a system of supply and return ducts. Supply ducts and registers (i.e., openings in the walls, floors, or ceilings covered by grills) carry cooled air