I keep my MTS in a metal bike shed, went out on it today and it was covered in condensation. Looking at buying a bike cover that is ideal for indoor use which is fully breathable to prevent condensation, come spring I don't want to find electric issues plaguing me. Most ones I,ve looked at are for outdoor use. The indoor ones tend not to be waterproof which is a small consideration considering the condensation in metal sheds.
Many years ago I too had a metal shed, and the general wisdom was to prevent the condensation by sticking those polystyrene tiles to the inside roof and walls. I'm not sure whether you can buy the tiles now, but I'm pretty sure that there are similar products used within the building industry insulation sandwiched between reflective materials that could be used instead?
The cheapest would be (metal structure) rockwool and polythene. You then need some method of keeping it close to the metal. Rope or put screws through it, after putting something like wood into the roof and walls to fix into. I've helped loads of people do this to sheds, the shed won't last as long as normal, but who cares it's just a shed.... I know people North of the Wall will find me heartless on this matter.
Celotex? Double sided tape... Insulation Boards - Walls & Floors Insulation - Building Materials | Wickes
Have you got power in the shed ? I have a dehumidifier and am amazed how much water it collects. I have to empty it 3 times a week. Keeps my tools from rusting as well.
i was going to ask about a dehumidifier.... does the garage/shed have to be "sealed" ? (as it will suck air out of outside else??) also is there any aluminium on the MTS (considering using degreaser in my spray wash snow mix in the winter) ?