Hey everyone! I'm located in Norway, where temperatures can drop below freezing for several months. I recently found out that I need to store my high-pressure washer above freezing to prevent damage, and I also have a robot lawn mower and several Ryobi batteries that I'm currently storing inside during the winter months.
I'm considering constructing a small storage cabinet insulated with 1-inch Styrofoam and using a 200W heater to keep the temperature from dropping too low. However, I'm unsure if just using Styrofoam for the walls is sufficient or if I should reinforce it with plywood or another material. Any advice?
5 Answers
When building your cabinet, make sure to seal it tightly to minimize airflow - that’ll help you keep the heat in. You might want to include a desiccant too to combat moisture. I’ve used a similar setup and found a 40W bulb can heat a small Styrofoam box to a cozy temperature pretty quickly!
Just a heads up — anything made from Styrofoam needs to be protected from UV light, or it’ll deteriorate. I suggest at least 3 inches of insulation; more is better since it reduces heat loss. Also, assess how powerful your heater needs to be; you might be fine with something as low as 6 watts! Considering your cabinet's location (inside a garage), a small fan blowing warm air from the house could be a helpful addition too!
Using just Styrofoam might be a bit weak, I’d definitely recommend going thicker than 1-inch for any insulation. If you want your cabinet to last longer, consider adding a more robust material like plywood for support.
Also remember to properly winterize your pressure washer; make sure any water is blown out to prevent damage. That way, your heater can be less of a worry!
I’d go for XPS instead of basic Styrofoam since it's tougher and has a higher insulating value. If you combine XPS with plywood, you won’t just get better insulation, but it'll also be much more durable. Just make sure your heater has a thermostat so it doesn't overheat, because while Styrofoam nowadays is more fire-resistant, you want to avoid any hazards!
I totally agree about the XPS! I read it’s safer with a fire retardant too. I plan to keep my heater set between 5-10°C, and yeah, humidity is a worry; I’ve got a dehumidifier ready!
I’ll definitely cover it with plywood for strength. My heater will sit at 5°C to start and cut off at 10°C, which should work well since it’s not near any heated spaces!