Where does good indoor climate design start?

Start with the room, not the air-handling unit

When I begin an indoor climate design, my first questions are about people and use. How many occupants will be present? What activities take place? Which pollutants, heat gains and moisture sources should the system handle? An airflow rate is a result of these decisions, not a substitute for them.

Make the criteria explicit

I define temperature, ventilation, humidity and acoustic criteria together. Air temperature alone does not describe thermal comfort: surrounding surface temperatures, air movement, clothing and activity also matter. CO₂ can help assess occupancy-related ventilation, but it does not measure every aspect of indoor air quality.

My starting point is a short, agreed design brief with operating schedules and assumptions. It makes calculations easier to review and gives commissioning a meaningful target. Equipment selection comes after that.