Creating a Tape Storage for Hot and Humid Climates
By Shubha Chaudhuri, Archives and Research Centre for Ethnomusicology, American Institute of Indian Studies, New Delhi, India
Creating a Tape Storage for Hot and Humid Climates
Creating a Vault
Creating a Vault (Cont.)
CHALLENGE: How to adapt a space for storing environmentally sensitive audiovisual media, which is not custom build for that purpose, within existing means and resources?
STRATEGIES: You prioritize your most sensitive collections, and adhere to prescribed practices for safe usage and access. With creativity and persistence you can achieve the desired results!
Creating a storage facility for audiovisual materials in hot and humid climates is a challenge, especially in spaces that are not custom built for archives.
This case study is about how a model storage facility was created for the Archives and Research Centre for Ethnomusicology of the American Institute of Indian Studies (ARCE from now forth) in a building that was originally a house. This facility housed the archives for 15 years – the period of perhaps maximum growth of the archives.
General recommendations from this experience have been applied to many other small institutions. This model is particularly relevant for institutions which have collections of audiovisual media but are not primarily archives and/or do not have the priority or in some cases the means of custom building a storage space.
The Archives and Research Centre for Ethnomusicology
The ARCE was established by the American Institute of Indian Studies in 1982 to create a centralized location for recordings of Indian music and oral traditions. Such collections had typically been made by foreigners in India and were thus held in archives in other parts of the world. Though Indian institutions were involved in recording and archiving such traditions, there were no archives that were open to taking in collections made by others. The focus of acquisition to date remains on collections that would otherwise not be available in India or those that are need of preservation. The Archives is thus based on voluntary deposit and has collections that are deposited by scholars, collectors and in some cases, institutions. The core of the collections consists of approximately 25,000 hours of field recordings, received on a variety of formats through the years. These are supported by a collection of published recordings, and a library that has books, journals, offprint articles, and a collection of newspaper cuttings. The archival collections also consist of documentation that accompanies such collections, as well as photographs, and ephemera.
The facilities at ARCE also include an audiovisual laboratory, and a listening and viewing room.
At the time that this case study describes, ARCE was situated in New Delhi, which is in the north of India and has a great range of temperature and humidity throughout the year, and at certain times of the year, throughout the day. The house in question was in a residential neighbourhood with moderate traffic, which had increased through the years. As a residential location, there was no extra space that could be specially built nor could drastic changes be made in a rented building. The power available for residential houses also does not support the electrical load required for running a large number of air conditioners, a few of these for 24 hours a day, 7 days a week. More critically there were a lot of temperature and humidity fluctuations and power outages in the area, and a lot of dust, which damages recordings and their playback equipment.
It is well known that variation of temperature and humidity is extremely detrimental to the longevity of physical audio and video media. Even in these days of digital media, these legacy materials still have to be properly stored.
Following the literature on preservation in publications such as the Journal of the International Association of Sound and Audiovisual Archives (IASA), and by having visited various international archives as well as having access to experts in the field, we knew what we should attempt. But the issue that remained was to meet the standards. We had to identify the range of temperature and humidity that we could sustain minimizing variation. By constant monitoring of temperature and humidity we could see what the range was and what we could try and achieve. The basic challenge thus was to provide stable temperature between 16 -18 degrees centigrade and 45% relative humidity, with relatively dust-free storage, and with low risk of fire. The over all constraint was also to achieve this in a low or modest budget. Even at that time (1985) lower temperature and humidity were considered desirable by international standards.
Creating a vault
The first step was to identify materials in the collection that needed constant environmental control and thus assess the space that would be required to store these, keeping in mind the rate of expected expansion which was approximately 1000 hours annually.
At the time we moved into this space in 1986, we had about a 1000 tapes consisting of audio cassettes and open reel as well as video on VHS. The collection grew to over 16000 tapes by the time we moved from the building in 1998 (to our current facility).
It was necessary that tape storage not be in a work area, which is often the temptation. Human beings give out heat, and their exit and entry to the room also cause temperature and humidity fluctuation. Equipment also gives out mild magnetic charge while they work, which could negatively affect magnetic media in the long run. Most importantly, staff find working in low temperatures uncomfortable and tend to raise temperatures or turn off air conditioners. Thus creating a small but dedicated storage, with 24 hour climate control was a must. Other areas could have air conditioners running during hours of work or as needed.
To start with, an appropriate room had to be chosen. We chose one on the ground floor towards the back of the house, which had the advantage of not having any walls that received direct sunlight. It was also situated next to the audiovisual laboratory, which meant that tapes did not have to be subjected to fluctuation as they went in and out of storage. The ground floor was also preferable as the weight of tape shelving per square foot would be considerable, and may not have been appropriate for higher floors that had not been built for the constant weight that this would involve. Finally, the back of the house meant it faced no traffic and thus air conditioners would suck in less dust and pollutants.
As this was a bedroom of the house it had windows and closets, and an attached bathroom. We sealed off the water connections to the bathroom, and made sure that water could not seep or drip and cause dampness in the room. We were also careful to choose a room that did not have a kitchen or bathroom with water pipes on the floor above.
Air conditioning and environment control
Two window air-conditioners were installed in the same window and the rest of the window was boarded up, as was the other window in the room. This helped to keep out heat, dust, and direct sunlight. The air conditioners were run in turn, one during the day and one in the night. This order was switched each week so that the same unit did not always run in the day, when the compressors have to work harder. This meant that neither unit had to run continuously, a practice that can cause breakdowns. Two units also meant that there was a backup in the event of one unit failing.
Though having air conditioners in the room constituted a compromise in terms of being a fire hazard, it paid off as window units are much more effective at controlling humidity than split unit air conditioners, as we found out when we moved to our current facility. A tabletop dehumidifier was also installed, which was very essential in the high humidity periods of the monsoon season and parts of the winter.
This system provided fairly inexpensive air-conditioning without a big airconditioning plant and air-handling units.
Electricity and infrastructure
The room was insulated with compressed particleboards from floor to ceiling, including with a false ceiling to reduce the height. A gap was left between the wall and the board, which was lined with fibreglass. The boards were painted with fire retardant paint. This is thermal insulation and helps greatly in conserving the temperature in the storage area.
We had to procure additional electrical load to run the necessary air conditioners.
All wires were run through polyvinyl chloride (PVC) pipe conduits externally so that any short-circuiting could not set the boards on fire. In order to provide backup during outages, the air conditioners were connected to a small manual generator that was stored in the garage outside the building. This ensured that diesel fumes did not get sucked into the archive, and the connections for the generator did not pose a fire hazard. The dehumidifier was however not connected to the generator (for only economic reasons!).
Fluorescent lights were installed with plexiglass covers to cut out the ultraviolet rays. The switches for lights were installed outside the room to further reduce the risks of fire through shorting or sparking. Also, it was preferable for lights not to be on when not required in the room, as ultraviolet rays are harmful to tapes.
Monitoring and workflow
Perhaps the most important requirement for running an archive is constant monitoring. Monitoring temperature and humidity gives a sense of how effective the air conditioning and dehumidifiers are performing and how to tweak the settings to get the best and most consistent results. We checked the temperature and humidity three times a day, once at the start and end of day and once at the peak of heat. Maximum and minimum thermometers also gave us a sense of the peaks during the nights and out of office hours.
It may seem that in many places dehumidifiers are not necessary, but lowering the temperature leads to rising relative humidity in even fairly dry climates. It is essential to keep in mind that stability is the key and thus choose a temperature and humidity range that is possible to maintain throughout the day and through the year.
Another critical measure is to plan the movement in and out of the storage space by limiting personnel who enter it. If this is well planned, taking out and putting in materials can be done when the temperature is being monitored so that it is not more than 2-3 times a day at the maximum. When there were power outages, we found that if the door was not opened, the temperature did not go up for about an hour, during which time the generator could be turned on. It is advisable to note the temperature and humidity at such times to measure the effect of any unusual activity or occurrence.
In time we extended 24 hour air conditioning to another small room which housed working copies and work in progress tapes so that the opening the doors of the archives was reduced further.
It is important to realize that all the materials in the vault or tape storage have to be at the required temperature and that it remains stable. Thus it will take a few months after setting up an area to attain the desired results.
This is a major challenge in most tropical countries. The main effort has to be to seal spaces from where dust can enter. Rubber sealants on the door are also helpful. Restricting footwear that is worn outside from entering may be considered. However, we found that the most effective method of reducing dust is daily vacuuming with an efficient domestic vacuum cleaner. This reduces the dust count gradually, and after a few years it can be observed that the dust that resettles after cleaning has reduced. After this point, daily vacuuming may not be required and can be brought down to a few times a week.
As dust is a major problem and as closed shelving enables temperature to remain more stable we decided to go in for closed shelving. The earliest shelving we had was wooden, but the shelves started sagging with the weight of tapes. We also learned about the possible acidic effects of wood finishes, as well as the danger of pests.
As the collection grew and it became harder to accommodate it in the one room, we moved to a novel solution of using enameled steel sports lockers (enamel finished steel is chemically inert and does not have acidic properties). This meant that the aisle space required was narrower and as each locker had its own door, opening a cabinet meant disturbing only the few tapes in the particular locker. This also meant that shelf spans were relatively small and not susceptible to sagging.
This is a major threat to collections, and safe and effective means of detection and suppression are expensive to install. In this case, we followed the prevention route. Smoke detectors were installed, and as described earlier, wiring was not internal but externally run through PVC ducting and switches were kept to a minimum. We also had a fire extinguisher installed outside as well as small and portable fire extinguishing aerosol sprays were kept inside where any small sparks could be extinguished.
The space described in this case study was the result of a few years of experimentation and provided a model for a few more archives such as the RupayanSansthan (Rajasthan Institute of Folklore) in India, RojaMuthaiah Library in Chennai, India, and the archive of the Music Department at Kathmandu University in Nepal, where the prohibitive costs provided by consultants had been a deterrent. The archives of the ARCE ran successfully with ideal temperatures between 14 to 16 degrees Centigrade and relatively low humidity for over a decade. Insulation, boarding and restricting entry go a long way towards helping air conditioners run more efficiently and hence lower electricity costs.
In 1998 the American Institute of Indian Studies moved to Gurgaon, just outside Delhi to its own campus. This gave ARCE the opportunity to have a custom built vault. The collections today have grown considerably and we have compact shelving with more than 25,000 items of recording, and a SAN RAID array based hard disk storage of 6 TB.
We have made use of the lessons that we learnt from our experiences in the facility described above, and though we have more advanced air conditioners with greater capacity and two compressors each, we still cycle them as before. We now have an air-handling unit that houses one air conditioner and the dehumidifier so that the cold and dry air is ducted in and there are no units in the archive storage space or vault. The other air conditioner is also outside the space with another duct.
Though the area was not built with windows, we have insulated the area with fibre glass and gypsum boards, and we maintain our monitoring procedures. We have also created as before a room where working copies are stored and ongoing work is temporary shelved.
The reliance on tape is in some ways not the same as before as we do not make masters on open reel or digital tape as the preservation is now digital. However it still remains important to maintain facilities for tape we continue to receive older collections on media such as open reel, many of which are in a fragile and brittle condition, and storing them in our vaults revives them to a considerable extent.Digital tape based media and Compact Discs too need the climate controlled facilit.
Being in a larger institutional facility had its own compromises , and its advantages- but that is another story and another case study!