What each route does
Forced ventilation expels hot cabinet air and draws in filtered ambient air, cooling by exchange; an AC unit runs a closed loop, cooling and dehumidifying the sealed cabinet air.
Applicable limits
- Ventilation: clean environments, wide temperature-rise tolerance, low load;
- Air conditioning: hot-humid, high-rate duty, tight uniformity requirements.
Energy and maintenance
Ventilation is cheap to buy and run but loads the filter and depends on ambient; the AC route costs more energy yet keeps temperature and humidity controllable and stable.
Selection advice
First calculate the cabinet temperature rise in the hottest month, then check local dust and humidity; when both bite, prefer closed-loop cooling with stronger filter maintenance.