I'm building a small 40x40x40 cm grow box that will be used mainly for seeds germination.
When operating, it will be completely sealed.
My question is: Is it safe to use polystyrene boards as direct insulation of the box? Because its main purpose is seeds germination, I need to maintain a stable temperature, for example, 30°C (86°F). To heat up the box, I'll use a heater made from a power resistor. I'm not sure yet what temperature of the power resistor will be at this moment; anyway, I'm wondering how safe is it? Or else, what could I do to make the polystyrene less flammable, maybe coat it with paint color?
Best Answer
30 degrees is fine, otherwise you'd be seeing melted polystyrene containers everywhere, especially around coffee machines.. The sheets can soak up water so it will need water proofing.