I'm about to set up my first growroom using a 400W HPS in a small closet. There is passive ventilation and I have a quality 4" inline RVK fan. Quite often you hear about grow ops being discovered after things catch fire. This is my home so I'm eager to avoid this Is there anything I can do to prevent fires, how do fires from a failing ballast usually occur?
Fires usuly happen because of poor electrical work, the balast getting too hot or turning the balast on too soon after it turns off. Get a High-temp shut-off relay, and a 15 minute time delay relay. Also using a sealed reflector will help reduce the risk of fire.