Hi, I'm going to build an insulated box, inner dimensions 900*600, for solar batteries. The box will be placed in a sheltered environment under a roof in an uninsulated barn. The temperature range for the batteries is -10/50 degrees C. We have a Frostguard 200w and there will be electricity to the box. I have access to thin MDF. So I need help with a suggestion/drawing on how to build the box! Ventilation holes? Styrofoam, how to attach it, are there better alternatives? Double layers of MDF with styrofoam in between? Generally handy but certainly not a carpenter!
Styrofoam can actually be glued, but mostly only with wood glue. That and "super epoxy". Since it's inside, regular "Casco wood glue brown bottle" will work well. You cut and glue the styrofoam when the wooden box is ready.T Tolle1234 said:
Then you make an outer mdf shell, styrofoam inside, and a (loose?) mdf board at the bottom for the batteries to stand on. Probably don't need inner mdf sides since you're not going to rattle around in there, just set down the batteries.
Lead-acid batteries need air holes.
Mice like to nibble on styrofoam and they like to peek into air holes. And (relatively) warm it is there too, which makes it a great place to live in the cold! There's often mm-mesh steel netting at hardware stores for the air holes.
It might be good if you have a couple of bars (45x45?) or battens for the box to stand on, off the floor. Then you can lift it if need be.
The frost guard should probably be mounted on its own batten a bit away from the styrofoam.
And an inner mdf board to attach fixtures to. If you don't have bars (45x45?) in the corners to fasten the board sides with, you can attach the inner mdf with long screws through the styrofoam to the outer mdf. And snip off what's protruding on the outside.
You might skip hinges, they're hard to align.
So. A drawing in the form of talk
Thanks, a plan is starting to form! Thinking of double boards with a 45x45 stud with Styrofoam at the bottom that I'll prop up with stone. Then an upside-down box as you described. Handles on the outside for lifting off. A ventilation valve maybe at the top and an MDF board on one inner side for the frost guard. A bit concerned if there's a risk for condensation?F farbror j said:You can actually glue Styrofoam, but almost only with wood glue. That and "super epoxy." It's indoors, so regular "Casco wood glue brown bottle" will work. You cut and glue the Styrofoam when the wooden box is ready. Then you make an outer MDF shell, Styrofoam inside, and a (loose?) MDF board at the bottom for the batteries to stand on. Probably no need for inner MDF sides because you're probably not going to be rattling around in there, just putting down the batteries.
Lead-acid batteries need ventilation holes.
Mice like to nibble on Styrofoam, and they like to peek into ventilation holes. And (relatively) warm it is there too, making it a great place to live in the cold! There are often mm-mesh steel screens at hardware stores for the ventilation holes.
It might be good if you have a couple of studs (45x45?) or laths that the box stands on, free from the floor. Then you can lift it if nothing else.
The frost guard should probably be mounted on its own lath a bit away from the Styrofoam. And an inner MDF board to attach fixtures to. If you don't have studs (45x45?) in the corners to screw the board sides together with, then you can attach the inner MDF with long screws through the Styrofoam to the outer MDF. And nip off anything protruding on the outside. You might be able to skip hinges, they are hard to align. So, a drawing in the form of a chat
A significantly less labor-intensive alternative is to use a second-hand freezer, insulated, metal-clad, and ready for immediate use. A couple of vent holes for the batteries can easily be made with a jigsaw or a Morakniv, and any frost guard can easily be screwed inside the box.T Tolle1234 said:
Condensation fpr
Maybe you should paint the box if you're anxious. But the log still stands, unheated but well-ventilated through 1-2 cm gaps between the boards, right? If it’s not dripping from that, the box shouldn't get wet either. Good idea with an upside-down box. No broken back then. But why prop up with stone? Natural stone is uneven and creates point loads.
Good luck anyway!
You can get condensation, for example, when the weather shifts from cold to warm and the box is cold.T Tolle1234 said:
Maybe you should paint the box if you're anxious. But the log still stands, unheated but well-ventilated through 1-2 cm gaps between the boards, right? If it’s not dripping from that, the box shouldn't get wet either. Good idea with an upside-down box. No broken back then. But why prop up with stone? Natural stone is uneven and creates point loads.
Good luck anyway!
Yes, that might work but we have most of the materials at home already, so we'll probably build it anyway. Just needed some tips regarding the styrofoam, ventilation, and frost guard. It's a lithium iron phosphate battery with an optimizer and it builds vertically, so the frost guard must fit as well.F fribygg said: