Application Story

Art galleries and climate control – one of the great facility management challenges. A gallery must make things comfortable for patrons, while ensuring the long-term safety and preservation of its artwork.

While people can easily adapt to a broad range of climate conditions, artwork is another story. Paper objects, for example, double their deterioration rate for every 14ºF rise in temperature. High levels of relative humidity (RH) will cause mold to grow and many metals to corrode. Fluctuating RH levels may also cause considerable damage to organic materials such as wood, leather, and ivory. These materials shrink or swell depending on the ambient RH. This movement can cause objects to split, warp, or crack.

As part of an effective climate control strategy, more and more art galleries and museums are using data loggers for continuous monitoring of air temperature and RH. Data loggers are compact, stand-alone devices that are equipped with a built-in microprocessor, memory for data storage, precision RH and temperature sensors, and a user-replaceable battery. Most data loggers interface with a computer and utilize software to activate the logger and view/analyze the collected data. And, because of their compact size, data loggers are often unobtrusive and can easily be placed in the areas of the facility where temperature and RH need to be measured.

One art gallery that has incorporated data loggers into its climate control strategy is the University of Toronto Art Centre. The Centre is home to three permanent art collections: the University College Collection (Canadian art), the Lillian Malcove Collection (primarily Medieval pieces), and the large and eclectic University of Toronto Art Collection.

In 1998, the facility underwent a major expansion that increased its size from 8,000 square feet to 16,000 square feet. While this gave the Centre more room for its changing exhibition program, it also meant that climate monitoring would be needed in more areas. “We use hygrothermographs to record temperature and RH in the lower levels of the facility, but upstairs in the gallery itself we wanted to go with something smaller and more aesthetically pleasing,” explains gallery curator Liz Wylie.

Wylie consulted with Sue Maltby, a local conservator who specializes in preventative conservation. Maltby, who had previous experience with HOBO® data loggers from Onset, suggested to Wylie that she implement two HOBO data loggers, one at either end of the 2,500 square foot gallery space. “The great thing about data loggers is that they are very small, and are not adversely affected by vibration,” she explains. “Hygrothermographs are very sensitive, and if you have twenty school kids coming through on a tour, the arm on the hygrothermograph might move up and down.”

Maltby also points out that in order to really understand your institution’s environment, you must be able to monitor your conditions all day long and throughout the year. “Spot measurements are great for telling you what the current temperature and humidity are, but what happens in the middle of the night, or when seasons change? I typically recommend data loggers for this purpose, especially in places like the Art Centre where a small, wall-mounted device is needed.”

At the facility, the HOBO data loggers are mounted at both ends of a 2,500 square foot section of the facility, which Wylie describes as a suite that is made up of six individual galleries connected by open doorways. The loggers are mounted at different heights – one at chest height and the other at knee height – in order to detect any significant fluctuations in airflow. Each logger is set to take temperature and RH measurements every 30 minutes. “We follow the international standards for temperature and relative humidity, so we need to keep our RH with a setpoint of 50% without a variation of more than +/- 5% in a 24-hour period,” she states. “For temperature, we aim to keep the gallery at a steady 21 degrees Celsius, +/- 3 degrees.”

After a month’s worth of data has been collected, Wylie retrieves the collected data using a data shuttle supplied by Onset. This pocket-sized device can offload and store the data from each logger, which Wylie then takes back to a computer for data graphing and analysis using Onset’s software. The software instantly translates the data into easy-to-read graphs that clearly show the temperature and RH readings for the month.

“The charts give us instant assurance about our climate conditions, and make it easy to document our conditions. This is important in situations where another gallery may want proof of our conditions before lending us artwork.”