Temperature

I don't know what a vaulted garage is. No ceiling? Uninsulated? Are you going to run train out there year round? If not, I would bring the trains in and store them in the winter. In fact, unless you are going to insulate and heat, I would pack everything up for the winter, track and all . I would be as concerned about humidity as temperature. If you are heating and wondering what to turn the thermostat down to when you are not in there, I would say 55-60.

Thanks will it’s a garage with poured concrete on three sides   Floor and ceiling and it buried in ground  so three sides and about two feet above ceiling is covered in dirt.  In summer it don’t get hotter then 75 degrees  and winter it gets cold I would say lowest it goes is 20 degrees. I run a Dehumidifier in summer and I do have a electric heater in there but don’t wanna heat it unless I have too 

The big enemy is humidity and rapid temperature changes.  It's not a big problem to store the trains in cold conditions, but if the temperature swings are large, that could cause condensation and of course rust and corrosion.  If you're not running them in the winter, can you store anything that's not nailed down in a climate controlled area?

Ok so if I keep a eye on humidity between 40 and 50 percent and temp swings will be between 30 degrees and 75 degrees and will put on heater when I wanna work on it. I should be good? I will use all year round looking to set up at 18 by 20 board. Just don’t wanna set up and have rusting or electronic problem so doing a lot of research. It isn’t insulted but it’s a unique garage cause it’s mostly under ground  the problem I have is when outside air heats up and walls are cold it condensates. But I put two heaters in and a dehumidifier  I haven’t had to put heaters on and humidity staying around 45 with dehumidifier on But hasn’t really got hot here yet.  

If you can keep humidity below 40% steel will not rust. As the temperature goes down the humidity goes up. Cold air cannot hold water as well as warm air, so it is the drop in temperature that causes humidity to go up eventually resulting in condensation or frost.  It is very hard to dehumidify cold air, so for most of us the only particle way to control humidity when it is cold is to add heat.

It’s wierd cause only see condensation when weather turns warm and walls are cold.  Not other way around.