Start with the room, filters, operating modes and maintenance.
Measure the room
Calculate the area of the room rather than the entire house. Published coverage is a starting point; room layout, ceiling height and ventilation also affect use.
Compare filters and modes
Check the stated filter types, replacement intervals and modes. Coway lists a Haze mode for Storm II and describes its Air Matching Filter programme as exclusive to Heart Service.
Keep expectations realistic
Laboratory test figures describe specific controlled conditions. Do not assume identical results in every home, and follow official local health advice during haze events.
Begin with the room you use most
A published coverage figure is a useful first filter, not a guarantee of performance in a particular room. Measure the room and consider whether it is open to other spaces, where the unit can stand and whether furniture may obstruct airflow. Ask the advisor to explain the product’s stated coverage and test conditions.
Plan for replacement and cleaning
Ask which filters the model uses, how replacement timing is determined and what the selected care plan includes. Follow the manufacturer’s instructions and consider the cost and effort across the intended period of use. During haze, consult current official local guidance for the conditions in your area.
Quick comparison
| Topic | What to check |
|---|---|
| Room size | Use the room dimensions as a starting point. |
| Filter care | Ask about replacement intervals and costs. |
| Operating conditions | Consider layout, ventilation and ceiling height. |