Maintaining an optimal climate in museum collections can be extremely tricky. Everything from the general climate of the region to types of items in the collection to the comfort of museum visitors and employees must be taken into account. Relative humidity is one key consideration.
According to an article by the Northern States Conservation Center that addresses temperature and relative humidity levels for museum objects, “there is no single relative humidity range that is ideal for all museum objects.” However, NSCC does recommend maintaining a non-fluctuating relative humidity (RH) above 25% and below 65% for mixed collections — noting that many museums maintain an RH of 45%.
Keeping a consistent relative humidity is crucial, as an RH below 25% “can cause embrittlement of hygroscopic materials such as leather and paper,” and an RH above 25% can lead to mold growth and metal corrosion.
For many museums, art galleries, and other collecting institutions, humidity control has involved expensive HVAC systems. However, these systems aren’t always the best solution for multiple reasons including budgetary and environmental concerns.
According to an article by Carol Kino at NYTimes.com, many art conservators are considering alternate methods for maintaining various collections. For example, Kino points out that the Victoria and Albert Museum in London has made a commitment to use more microclimate cases. These are vitrines “that keep groups of similar objects at their own specific humidity levels, so that the air in the rest of the room does not have to be conditioned so stringently.”
Another effective solution involves the use of a dehumidifier. Dehumidifiers come in a variety of humidification capacities — from industrial-grade units, such as the Hi-E Dry 195 Dehumidifier, which can be ducted to dehumidify multiple areas, to compact, portable units, such as the Santa Fe Compact Dehumidifier, which are designed to maintain RH levels in smaller spaces.
The Hi-E Dry 195 is a commercial dehumidifier that is capable of handling heavy-duty humidity problems as well as common ones in large spaces. The unit removes 183 pints of moisture per day under AHAM conditions and 366 pints per day at saturation, using just 12 amps of electricity. Plus, it operates effectively in temperatures as low as 33 degrees Fahrenheit.
One of the best features of this high-efficiency dehumidifier is its versatility. The HI-E Dry 195 can be used as a stand-alone unit or ducted. If aesthetic appeal is not an issue for a collection, the 195 operates like any plug-and-go product, with no assembly required. However, if you want to hide the dehumidifier, save valuable floor space, or even dehumidify multiple areas, this Hi-E Dry dehumidifier offers several ducting options.
If you have a smaller collection or just need a smaller unit, the Santa Fe Compact is another great option. Originally designed to combat humidity and mold problems in tight crawl spaces, this tiny unit, which measures less than two feet wide and only a foot high, removes up to 65 pints of moisture from your environment each day under AHAM conditions and up to 130 pints at saturation. Thanks to an Energy Star rating and the environmentally-friendly R-410A refrigerant, this dehumidifier also helps save energy and protect the environment.
If ducting is an option, the Santa Fe Compact’s innovative design also allows multiple configurations. You can configure this compact dehumidifier to remove moist air from one area and deliver dry air into another. Another ductable dehumidifier is the new Santa Fe Advance 2 Dehumidifier, which is extremely common in crawl spaces and basements because it offers low-temperature operation, removes up to 90 pints of moisture a day, and covers up to 2,200 square feet. Check out all top-of-the-line Santa Fe dehumidifiers and see if any work for your space.