The Darwin Chambers AR series is designed specifically for the needs of archival preservation. This series is capable of providing long-term controlled storage of photographs, film, rare books, papers, and paintings. Utilizing a simple precisely controlled refrigeration system and advanced desiccant-based dehumidification, temperatures are maintained to within ±0.2ºC (at the sensor) and relative humidity to within ±1% (at the sensor). Not only is this series of chambers perhaps the most precise, but they are also exceptionally energy efficient for the high performance they offer. Typical uses and temperature ranges the AR series is capable of providing a solution for all as follows: Books, papers, and paintings: 10ºC (50ºF), 30% RH Film,photographs, microfilm: 1.7ºC (35ºF), 35% RH The above settings are somewhat typical, but there are many different desired set-points, depending upon the nature of the preserved media. Anywhere within the range of 0ºC to 25ºC (32ºF to 77ºF). Relative humidity can be controlled at any percentage from 10% to 60%, within an allowed dew-point range of -12ºC to ambient. The standard chambers do not include humidification (this can be added as an option for unusual applications), as they are normally not needed to maintain lowered dew-points. Check out this awesome website that goes into a little more detail about preservation basics and the vinegar syndrome: National Film Preservation Foundation.