My wife and I have a baby on the way, and my collection is getting booted to make way for a nursery. Is there any harm in storing my coins and currency in an attic that does NOT have HVAC? The Place: My attic is well insulated but does not have air conditioning or forced air heat like the rest of the house. It does have radiator heat (oddly, they left that there when the HVAC was installed in the 1950s). The air temperature can go as low as 55-60 F in the winter and as high as 120 F in the summer - same temperature as the outside. The Collection: I don't own any slabs. My coins are either loose, in Intercept Shield / Dansco albums, or in 2x2 mylar flips stored in a large wooden footlocker. My currency is placed in plastic pages and stored in a 3-ring binder. I have some currency in paper envelopes. Any thoughts on whether I could put my collection in the attic? What are the problems with temperature differences? Humidity is NO problem... even when its humid outside the house is comfortable, if hot. Coins are ultimately just hunks of metal and currency is just paper, right?
You misunderstand me... when I say "humidity is NO problem" I mean the area where the coins would be is not humid. It can be swealtering outside and the attic is fine. Just hot.
YES ! Probably worst thing you could do. Coins need to be stored in an area where the temperature rarely changes. And in an enclosed container like a safe or a large Tupperware container so the humidity inside the container can be regulated and kept as low as possible with silica gel packs. And it is best to store them in the dark. If you can, find a closet in you home that has no walls that border on the exterior.
I'll echo Doug and Cody.........don't store that collection where there are going to be major swings in temperature.
Daily fluctuations in humidity or heat can cause condensation. Coins are highly conductive and moisture is therefore more likely to form on their surfaces if not sealed from the environment. In other words, an attic is a terrific place to corrode coins and rot currency. If you are unaware of these fluctuations, buy a small digital temperature AND humidity gage for both indoor and outdoor from the local home improvement store ($35) and observe the fluctuations hourly for a day or two. Turning off your HVAC at night or on vacation destabilizes the temperature and humidity to a lesser degree. Anyone with valuable coins, paper, art, cloth, wood, musical instruments, etc., should seriously consider keeping the HVAC about the same temperature and humidity 24/7. During dry seasons, the air should be humidified and during wet seasons dehumidified. (Plus, it feels better!) This approach is not free, but might be more cost effective than the damage by decomposition or corrosion of valuables. Museums take this approach. It may be simpler to isolate the valuables in a small room with it's own localized conditioning system if the home does not have a central system. You may be surprised to learn that maintaining 24/7 isn't that much more expensive. Some people think they save energy by opening all the windows at night. But in a high humidity location (like the US Southeast), this re-introduces a tremendous amount of energy back in to the house (in the form of humidity) that the system just spent the entire day extracting. It doesn't cost that much to cool at night since it is so much cooler. The bigger benefit to collectors is that this greatly reduces humidity spikes!
It is actually cheaper to set your thermostat at 1 comfortable temperature and leave it there. This is not an opinion.
