Bill,
I have a 20’ X 20’ attic layout in southeast PA. I used foam roof baffles, collar beams and insulation. I have both a ridge vent and gable end vents (actually the gable end vent in the train room is a Broan 353 fan with a Broan 433 shutter).
There is no good way for me to install AC so it gets way too hot in the summer. When I use the attic gable fan it gets kind of bearable.
In winter, when not being used, the train room is usually a good bit warmer than outside. Before I operate the trains, I open the train room door and use a portable fan to blow house air into the room. Also use a 1350 watt portable electric heater. I haven’t had any problems with ice dams.
You asked about how cold is too cold an environment for electric trains to live in. There are several strings and as many opinions on the forum about attic train storage. I haven’t had any problems with keeping trains in the attic (no train problems due to living in a cold / hot attic). Although I don’t keep my prewar stuff in the attic.
I built the platform about one foot off the floor to maximize the layout size. That makes it difficult to run any wiring under the platform so if I had it to do over I would make it a few inches higher and sacrifice some layout size.
Bob
