Yearly cleaning makes sense in a condo because the vent run is not always easy to see from inside the unit. In our building, one neighbor noticed warm laundry room air and longer drying, then the board started asking about shared safety checks. I searched for a condo-focused service and found https://dryerventcleaningtoday.ca/condo/ while comparing what technicians usually inspect in multi-unit setups. The part I liked was that it treated the issue as building maintenance, not just one owner’s dryer problem. After cleaning, drying felt quicker and the hallway no longer had that warm lint smell. I would not wait for smoke alarms or a serious warning. Once a year feels reasonable, especially when many units use dryers every week regularly.