I am bulding a simple drying oven with dimensions 6′ x 2′ x 2′. The oven needs to operate within a temperature range of 150 F ~ 200 F.

Construction of the oven will consist of Al or Steel walls with a 2.5" thick mineral wool insulation & the temperature will be maintained with a PID controller connected to a thermocouple.

When I used the Oven temp time to rise calculator excel sheet, I got a rise time of 30 second with a 500 Watt heater element. I am having trouble selecting a heater element. Should I go for an infrared heater light with 500 Watt capacity or a heater element that is normally used in a conventional oven with 500 Watt capacity? Any suggestions?

How can I maintain the the oven temperature at a particular value? Will the PID controller turn the element on and off too many times & in the process damage it? Would I need to put vent holes in the oven to allow circulation?