Temperature and Relative Humidity

How often do we wish for the perfect lives, the perfect job, or even just the perfect situation? How often does that perfection happen? Yeah, well, it’s no different with museums. In the museum field there are many goals or best practices that we try to achieve. While we strive to reach these best practices there are many factors that complicate the situation including time, money, and man-power. The best practice that I want to discuss now is the control of temperature and relative humidity (RH). As of right now it is accepted throughout the field that the ideal temperature in a gallery is 70 degrees Fahrenheit + 2 degrees and RH is 50% + 5%. As you can see there is a little wiggle room but the temperature and RH should not vary more than that + 2 or + 5 respectively within a 24 hour period. With improper temperatures and RH or too much variation the objects are put in jeopardy and things such as drying, cracking, swelling, mold, corrosion, and warping can occur. If you noticed I said that these are ideal for the galleries. Storage areas in museums should generally be cooler in temperature if possible. A cooler temperature will usually prolong the life of an object. A cooler temperature, on the other hand, is not usually appreciated by visitors or staff. People ordinarily don’t just hang out in a storage area so the cooler temperature is preferred but people are in and out of the galleries all day which is why the temperature should stay more comfortably around 70 degrees Fahrenheit. Your patrons will appreciate it.

There are many ways to control temperature and RH like microenvironments, silica gel, and HVAC systems but I’m not going to go much into those right now. We have an HVAC system here but this is such a dry, warm climate that keeping the temperature and RH at the right levels can actually be really difficult. Usually our temperatures aren’t too bad but our RH can very dramatically within the day. Interestingly enough, things like our bronze sculptures do better in a dryer climate but our leather saddles need more moisture or they will crack. This is why 50% for RH is considered best practice. The funny thing is that all this rain we’ve been having lately has caused our RH to more or less be practically ideal (we’re still varying more than we should but at least it’s around 50% and not in the teens like usual), but for that same reason we’ve had leaks. That’s right: leaks! The main thing I’m thankful for right now is that for the most part the leaks have been in the entry way and hasn’t damaged any artifacts *knock on wood* although it has been really close to our kiosk computer system. We do watch this closely and we are talking with our maintenance people to see what can be done, but we hardly ever get rain like we’ve had so it’s probably not at the top of their list especially when other buildings on the New Mexico Junior College campus (of which we are a part) leak. The best that we can do is to keep an eye on the situation, record/report any new leaks, and move furniture and artifacts as needed. You know, if it’s not one thing, it’s another. It does help knowing that we are not the only museum with troubles like this. Anytime I talk to my friends in the field I hear their stories and realize all over that we are not alone and if it wasn’t RH and leaking problems it would/could be something else. For now, I’ll take what we have because at least we know what is happening and we can try other methods to control the issues.