Noel, A quick answer is "the longer the better." I have been fortunate enough test and proof a new HVAC system for a year (over all four seasons) before artifacts were moved in, as well as having artifacts installed after only a month of monitoring during one season.
It is not so much a question of how long to proof HVAC equipment as it is “when” to proof. In your climate, your need to test and proof the equipment during winter (heating and humidifying), summer (cooling and dehumidifying) and either spring or fall, the seasons that place the most strain on your system as conditions swing between warm/cool and dry/humid. Independent commissioning of a new HVAC system is important to minimize the wait time required to introduce objects to the space. But even with a good independent commissioning agent, be sure to plan for at least two commissioning periods, one in spring-to-summer as the AC/dehumidification mode kicks in and again in fall-to-winter as the heat/humidification settles in. Although each of the separate functions can be tested for a day or two at any time, the systems cannot be properly proofed until they are closely observed repeatedly switching between the heating/humidification and cooling/dehumidifying functions. Finally, it also depends on the type of objects to be exhibited in the gallery and the cases protecting the objects. An exhibition of stone sculpture, stable glass or ceramics could be mounted shortly after a new system is commissioned. A historic house room where unglazed paintings on canvas or ivory miniatures were to be displayed would require a very well-proofed system over at least three seasons. It is best practice to advise curators to plan an exhibit of stable objects that are robust to environmental changes exhibited in cases or vitrines in a newly conditioned space. This allows for adjustment of controls and equipment over two or three seasons while reopening the space to the public with little risk to the objects. Feel free to contact me offline if you would like to discuss this further. Richard Kerschner Kerschner Museum Conservation Services, LLC 3532 Shellhouse Mountain Road Ferrisburgh, VT 05456 (802) 236-5564 [email protected] ****** Unsubscribe by sending a message to [email protected] Searchable archives: http://cool.conservation-us.org/byform/mailing-lists/cdl/
