Questions about racks

[DanielSan]

Hello I have been a while thinking about building a rack and I have been looking for some information to do it my self.
So far i just bought the containers they are around 70x40x20.
My questions are:
I live in the northern part of spain, in winter i have around 41º F and in summer around 25-30 somedays. My question is what kind of structure do I have to build(wood, aluminium or pvc), how much ventilation.
I pretend to give heat with a cable and i have a thermostat. How is the best way to put the cable?
Please give me a hand

[PitOnTheProwl]

Ventelation will vary from house to house, thats something you will have to figure out.
If you are going to try and use cable you will need to figure out how to inlay it into the shelf.

[DanielSan]

Ventelation will vary from house to house, thats something you will have to figure out.
If you are going to try and use cable you will need to figure out how to inlay it into the shelf.

Thanks PitOnTheProwl, I thought about how to inlay the cable and I think i found a solution, I am putting the cable with a metalic adhesive tape and then put some cardboard for more easy way to pull in and out the plastic box without touching the cables directly, Is it a good idea?

And about the structure i have my doubts. I dont know if its better doing it open or closed. I mean like https://www.google.es/search?q=homem...ml%3B640%3B480 or like this http://www.google.es/imgres?imgurl=h...art=71&ndsp=18

Thanks for everything

[Darkbird]

For the cable, if you don't have a way to cut slots for it in the wood, I would add an extra layer of plywood to each shelf, say a 1/4" thick, that only goes back to where your hotspot begins. The cardboard will wear and eventually collapse, and you may not realize there's an issue until it's already damaged the heat cable.

[CORBIN911]

If you insist on cord rather then THG heat tape, You could go to a local hardware store and pick up a Hand Dremmel, prolly like 39-45$ and it'll work miracles for the entire builds process!