 It's to you, your host, Susan Barger from the FAAIC. Go ahead, Susan. Hi, everyone. This is our last webinar of the year. And so keep an eye on the website for what's coming up in 2018. The very best way to keep informed about what's going on with us is to join the announce list. It's only two or three messages a month, and it's not a chat list. So if you're not on it, please join it. And you can follow us on Facebook. You can like us on Twitter. And yeah, you know what that is. And if you have a question and you want an answer, there's an army of young conservators that answer questions. So feel free to send in questions to the discussion forum, and you'll get an answer quickly. And on the discussion forum, people ask about how they can be kept up to date. And so once you sign into the discussion forum, you can click on email options, and then you can decide how you want to be notified if there's something's going on. And also from time to time, we're asked about closed captions. We have closed captions on most of our webinars. We add them after the webinar because they're more accurate. So if you see a closed caption sign like this, or if you see this, you can click on this link. It takes you to the ARC YouTube channel, and then you can click on the closed caption, and you'll get it. So that's available for you. And probably all of the webinars through this year will be captioned before the end of the year. You can always contact me. This is my email address. And coming up in 2018, we're going to have something on strategic planning in January. Two webinars in February, one on security, one on the much-promised webinar in Ivory. And there's going to be one on Globes coming up, some on emergency planning. So keep an eye out for what's going on. Now I'm going to turn this over to our speaker for today. That's Alice Carver-Cubick. And so Ted. OK, thank you very much. Yeah, my name is Alice Carver-Cubick. I'm a research scientist at Image Permanence Institute. My background, my education, my master's degree is in collections management and preservation. And I originally came to Image Permanence Institute to work on Graphics Atlas. If you're not familiar with Graphics Atlas, it's a photograph and print identification and characterization resource. It's online. It's pretty cool. So yeah, check that out. But now I'm doing that, and I'm also doing some other areas of research, which is part of what I'll be talking about today. OK, well, so my task today is to give you the big picture of storage environments for libraries and archives. So if you've ever stood in front of this painting by David, its impressive size is really almost overwhelming. It's a big picture. I'm going to try not to overwhelm you or to overwhelm myself in introducing the big picture of environmental management. However, I have to warn you, there's going to be lots of graphs. But don't worry, we'll walk through them together. Much of the information I'll be sharing is based on research we have done at IPI, Image Permanence Institute. We are an independent not-for-profit university-based research lab. We're located at the Rochester Institute of Technology in Rochester, New York. We are a recognized world leader in the development and deployment of sustainable practices for preservation of images and cultural heritage. And we do this through a combination of research and education and consulting and training and things like that. So what I'm presenting today is a culmination of all that we've done in terms of looking in environment. So this slide is really just an outline for the presentation, what I'll be talking about. By reviewing the types and causes of decay, we are reminded of why environment matters. Next, I'll discuss what a preservation environment is, followed by a discussion of the research behind our recommendations for certain environmental parameters. I'll then offer some strategies for maintaining a sustainable approach to environmental control. And finally, I'll give a sneak peek into what questions we still have and how we hope to answer them. So how do collections materials deteriorate and what causes them to deteriorate? There are three types of decay, chemical, mechanical and biological. Most of you already know this, but again, a review is always really nice. Chemical decay is sometimes referred to as natural aging. Sometimes it's natural and sometimes it's induced by environment or other factors. Essentially, it's deterioration due to chemical reactions occurring within the object. It is our goal to slow it down or to stop it. Mechanical decay deals with the physical structure of the object. Some mechanical damage is also induced by environment and some is due to handling of the object. Biological is primarily induced by environment, whether it's mold or insects, other vermin like mice and rats or another issue. Typically we identify the main causes of decay as light, heat, relative humidity and environmental pollutants. In managing our storage environments, we focus on managing temperature and relative humidity while paying close attention to dew point. There should be little to no light in the storage environment when it's unoccupied. So these will be my focus here. So let's start with temperature. High temperature leads to chemical decay. Heat is a form of energy. In order for many chemical reactions to proceed, they need energy to push it forward. Heat causes molecular bonds to stretch and break. Chemical bonds are easier to break at high temperatures and sustained high temperatures increase the rate of chemical reactions. The rate of decay doubles with every nine degrees Fahrenheit increase in temperature. So the image that's shown here, let's show another little arrow. So the image here is really illustrating the ideal gas law, showing the correlation between heat and pressure. As heat increases, the kinetic energy of the atoms increase, thus increasing pressure. The rate of chemical reactions that lead to deterioration follows a really similar model. As heat increases, the reaction goes faster. So as a result, dyes fade, plastics degrade, textile fibers weaken and break, paper fibers also weaken and become yellow. But this type of chemical deterioration is really slow. Relative humidity is a measure of the amount of water in the air compared with the maximum amount of water that can be in the air at that temperature. In short, it represents how saturated the air is with water vapor. Temperature and relative humidity are related. Warmer air can hold more water. So this illustration shows a constant amount of water at different temperatures, which results in different relative humidities. So my arrow is not moving for me. Oh, I see, okay, there we go. So here we have the same amount of water, different temperatures. So at 55 degrees, this amount of water equals 100% relative humidity. But at 80 degrees, it's only 42% relative humidity. So the humidity is sort of the ratio between the temperature and the amount of water vapor that's expressed as a percentage. Okay, dew point. Dew point is a measure of the absolute amount of water in the air. It is also the temperature at which the air can not hold all the moisture in it and water condenses. Sometimes it's referred to as dew point. Sometimes you'll hear the word dew point temperature. It's the same thing. The outdoor dew point and the indoor dew point are the same unless the air is humidified or dehumidified. Dew point determines the temperature and relative humidity combination that you can achieve. So when we look at this pretty awesome cartoon that I've actually found on the internet, what we see is the temperature is 53 degrees and our dew point temperature is 51 degrees. As the temperature drops, we get closer to the dew point temperature. When our outdoor temperature matches the dew point temperature, we get condensation. The air actually, the water comes out of the air. When I was practicing this webinar to a couple of colleagues, both of which work in museums and curators, collections managers. And when I got to dew point, they were both like, yeah, so dew point, I'd never get it. So I thought, okay, how do we do this better? And I thought, well, we experience dew point in our everyday lives all the time. So one really good example is in the summer, if your house isn't air conditioned, it isn't dehumidified, such as mine. If I want a cold drink out of the refrigerator, maybe I'll get a cold bottle of soda out of the refrigerator. Within a really short amount of time, the outside of the bottle is wet. And that's because the interior of the refrigerator, that environment is much cooler than the environment outside. And I'm hitting dew point, right? As the bottle warms up to the temperature of the outside air, I cross this, right? I cross dew point right here, and I get condensation. Another really good example was I was hiking in a state park and it was really hot, muggy day. And I went into an interior space. It was a cinder block structure. And cinder block structures are really great for keeping sort of the interior space cool. A lot of buildings in the Southwest are cinder block. So I entered the cinder block structure where it was much cooler inside than it was outside, but the dew point temperature was the same throughout. Remember I said the indoor and outdoor is the same unless you dehumidify. And so when I looked at the walls, the walls were, there was condensation. The walls were totally wet. So we had hit dew point. We had crossed that line. So essentially you just don't want that to happen to you. You don't want that to happen in your collection. And I'll sort of keep going and explain how you know when you hit dew point or how to avoid this. So temperature and relative humidity can be measured. No instrument can tell you the dew point. The dew point is a result of the temperature and relative humidity. And this is the factor that HVAC engineers as well as collections managers are really looking at. There are sort of indirect ways of calculating dew point. You can use a hygrometer which has this polished mirror and when the mirror cools, you get condensation on it. And then you can be like, oh, there's the dew point temperature. There's psychrometers. There's also, if you know the temperature and relative humidity, there's a really complicated calculation that's calculus which you can calculate the dew point. But, there's also, I also want to point out here, this is dew point, right? We have 100% relative humidity. So that's your dew point as well, right? That's when it's going to condensate out. But anyway, going back, yeah, there's all these complicated ways of calculating dew point or you can use the dew point calculator. This is a resource that's free and available online. It's an IPI resource, dbcalc.org. And, get rid of my arrow here. And yeah, all you have to do is dial in your temperature and relative humidity and it'll tell you kind of what your dew point is. And so, if you're an HVAC engineer or if you're a collections manager or whatever your job is, you have to pay attention to dew point, use the dew point calculator. The other point I want to make out here or I want to make here is, because there's a relationship between temperature, relative humidity and dew point, if one of these factors changes, the others change as well. So as air heats up, it can hold more water, which we saw in the previous slide. At a constant dew point, when the temperature goes up, the relative humidity goes down and when the temperature goes down, the relative humidity goes up. So institutions that try to improve conditions by lowering temperatures without really looking at the dew point or the resulting relative humidity may find that the moisture level is much too high for safe storage of vulnerable collections. So, that's pretty much what this is showing. Let's say our temperature is 68 degrees Fahrenheit and our relative humidity is 40% and we have a constant dew point of 42. We decide, gee, I'd really like our storage environment to be cooler, let's drop it down to 50 degrees Fahrenheit. We'll look what happens to the resulting relative humidity, right? We end up with 76% relative humidity, which is high. So as a basic rule, the higher the dew point, the harder it is to maintain cool temperatures and moderate relative humidity. This is dew point is typically the limiting factor of mechanical system capabilities. So hopefully, you've got to handle on dew point now. Within the handouts that have been provided as part of this webinar, we have a handout that describes dew point. So definitely download that and check it out. And if you have any more questions, feel free to ask. I'll answer all the questions at the end. For the rest of the presentation, I'm going to put a lot of emphasis on water. In most circumstances, water is a really great thing. For your collection, water is the cause of much of the deterioration seen in collections. In thinking about the causes of decay, temperature and water are the most important factors. We're interested not only in how much water is in the room as measured by the ambient relative humidity, but also moisture content of your collection. That is how much water is potentially in the collection material itself. Much of our collections are composed of hygroscopic materials, materials that readily absorb and desorb water, such as paper, parchment, leather, cloth, and photographic gelatin. Extreme changes in moisture content cause collections materials to expand and contract, potentially causing permanent physical deformation. High temperature and acidic environment catalyze hydrolysis, a chemical reaction that is the major cause for deterioration in organic materials. Hydrolysis is a reaction with water resulting in the formation of one or new substances. So if the relative humidity is elevated and you have high temperatures, that means that there's more water available. The reaction is then accelerated in the presence of an acid. This acid can come from the material itself, like lignin in poor quality paper or the sort of byproducts of deterioration in cellulose acetate film. It can also come from poor quality housings or it can come from air pollution. Acid hydrolysis is a concern for organic materials, like cellulose materials like paper, as well as some plastics. Moisture is also the major factor behind biological decay. Mold will grow above 65% relative humidity. Active mold should be taken really seriously. It can be absolutely detrimental to collections, really to the whole collection. Mold is not temperature dependent. Although high temperatures will absolutely accelerate the formation at mold, as my colleague, Dugmesha Murrah says, he's got mold in his refrigerator. And admittedly, I also have mold in my refrigerator. And you've probably also experienced mold in the refrigerator. So it's a humid space and you definitely don't need high temperatures for mold. So here is the ugly face of deterioration in which water is our main culprit with help from its evil front temperature. The book on the left is experiencing paper deterioration, likely as a result of hydrolysis. I want you to notice that the yellowing is happening from the inside out. This is common as moisture will penetrate from the edges first. Next, we have mold on photographic material. I believe that's a gelatin printed out print. Then we have cockling of a photograph due to extreme expansion and contraction of material due to water absorption and desorption. Again, we have hydrolysis of cellulose acetate film in our second row. And these last two images here and here are mechanical deterioration due to extremes in relative humidity. So now that we reviewed the types and causes of deterioration, let's talk about preventing deterioration. Temperature and relative humidities are the factors that we can manage and we can measure. Cool temperatures are better. Relative humidity should be moderate to avoid excessive moisture or excessive dryness. We should always keep an eye on dew point to determine safe temperature and relative humidity combinations. Again, use the dew point calculator. What's more difficult to discern is when your collection material feels a change in environment and to what extent does it feel the change. Because water is the culprit for most deterioration, another factor we must consider is managing the moisture content of the collection materials. Like dew point, this can't be measured directly. For a long time, many collection collections, excuse me, for a long time many collecting institutions took a static approach to environmental management. Typically, this means keeping conditions at a steady temperature and relative humidity, usually 70 degrees Fahrenheit and 50% relative humidity, which is intended really for human comfort. This is a problematic approach for several reasons. The first and most important reason is 70 degrees Fahrenheit is far too warm for your collections. 70 degrees Fahrenheit is the temperature at which hydrolysis begins. Again, hydrolysis is the primary form of deterioration for paper, cloth, and other organic materials. Other collections maintain constant conditions at cooler temperatures of 60 degrees Fahrenheit and maybe 40% RH. There is absolutely nothing wrong with maintaining these conditions. This will provide a really good preservation environment for most library and archive collection materials. Maintaining a static environment, however, also uses an incredible amount of energy. In non-temperate climates, the HVAC systems are constantly fighting the outdoor highs and lows in both temperature and relative humidity. HVAC systems are not typically designed for this. The energy usage translates not only to a huge carbon footprint, but also to money. Maintaining constant conditions is really expensive. So again, in terms of achieving the goal of all collecting institutions, providing the best preservation environment we can to help these materials last as long as possible, a static approach at cool temperatures and moderate relative humidity is absolutely fine. However, cultural institutions are facing financial constraints due to a lot of factors. HVAC operations are a big bill for most institutions. I think the HVAC bill for most institutions are as much and often more than even staff salaries. So we're talking major money, which I'm sure you're well aware of. So when thinking about how we manage the environment for collection storage facilities, we have several really legitimate concerns. And they are, what are the upper and lower limits for temperature and relative humidity? What is meant by avoiding extremes? What is happening to the collection materials when there is a sudden change in environment due to equipment failure or a power outage? What is happening to the object when we bring it from one environment into another environment in order to provide access? What about slow changes in environments that occur over several months? It's these often unanswered questions that lead us to airing on the side of caution and pushing toward a static approach to environmental control. What I hope to show you is that through our research, we have found that many of these concerns are not as frightening as they seem. Okay, so what is the big picture? I promised you a big picture. Sustainability is the name of the game. Because energy costs continue to rise and squeeze the already tight budgets of collecting institutions, we need to figure out ways to maintain a high level of preservation for our collections while saving on energy consumption, which in turn will save money and reduce our carbon footprint. We do this by taking what's called a dynamic approach to environment. A dynamic approach means set points are adjusted seasonally in order to keep spaces cooler and drier in the winter and warmer and more humid in the summer while staying within the temperature and relative humidity parameters that are considered acceptable for maintaining a preservation environment. Depending on your geographical location and your building envelope, this may also mean nightly and weekend setting adjustments. Some institutions change the set points, so change like their temperature and relative humidity levels. And some actually shut down their HVAC system during nights and weekends when the building is unoccupied. This can be particularly effective in institutions when the collection space and staff or visitor spaces are shared. And we're gonna go more into detail about this, talk more about this. But the first thing I wanna address is chemical stability. So first thing we need to do is keep our temperatures low. There are safe and risk zones for temperature. Temperature can fluctuate within the safe zone, the green and yellow here. Managing high and low temperature extremes is more important than maintenance of steady temperatures year-round. I'm gonna say this again because this is really the important point we need to make here. Managing high and low temperature extremes is more important than maintenance of steady temperatures year-round. So essentially we don't want to get here. We don't wanna be 20 degrees Celsius, 68 degrees Fahrenheit. We wanna stay within this sort of, 55 degrees or lower. So generally cooler temperatures are better for preservation. However, some materials should never be in frozen storage. That's what we have down here. This is our frozen storage. For example, some photographic processes, glass plate negatives or internal dyed fusion transfer prints more commonly known as our Polaroid XX70 should not be frozen. And paintings, for example, should be kept above 54 degrees Fahrenheit. In a mixed storage situation, you wanna get your temperatures as low as you can for the collection materials you have. Okay, the second thing that we wanna look at is relative humidity. We want to avoid extremes for long periods of time. High relative humidity equals more risk for damage. And RH of 30 to 55% is really good for most collections, particularly collections made of hygroscopic materials. Extended low RH below 25% can eventually lead to the loss of bound water. Bound water is the water that's necessary for the flexibility of objects. And it's actually necessary for the molecular structure of the object. If you lose this bound water, it'll lead to permanent damage due to brittleness. It can also lead to contraction of the object and possible mechanical damage. Extended periods of high relative humidity, our primary concern again is mold, but we can also get expansion and contraction or extreme expansion. And again, if we have our temperatures high, we have all this water available for chemical deterioration for hydrolysis. Like temperature, relative humidity can fluctuate within these safe zones, within that 30 to 55%. The important thing to take away is to avoid extremes for long periods of time, to avoid 25% or lower, to avoid 65% or higher, right? We don't want this for long periods of time. And I mean like a month or more. Because your collection will not actually feel short isolated incidents. How do I know this? I'm going to discuss some of our research findings that lead to these facts and the justification for our dynamic approach to environmental management. Our research as well as research by other institutions in the United States and in Europe, all point toward adopting a sustainable and dynamic approach to environmental control. And so these are the facts that I'm going to to sort of expand upon. Thermal equilibration is fast. Moisture equilibration is slow. Ambient relative humidity will have an impact over really long periods of time. Enclosures help. There's a relationship between temperature, the relative humidity, the dew point, as well as your collection materials. So before I get into sort of expanding on these facts, I want to sort of tell you a little bit about the experiment that we did. In which we kind of came to these facts. So shown here is a graph of a temperature and relative humidity profile used in our experiments. The profile was designed to represent eight hour and 16 hour setbacks. That means that the temperature set point was changed at times when the institution would be closed. The relative humidity profile was a mirror image of the temperature profile. This is what we expect to see at a constant dew point when only the temperature changes. This will also maintain a constant moisture content in the room. So I'm going to actually walk you through this graph. So what we have here is, you know, this is our profile. The graph comes from Eclimate Notebook. Eclimate Notebook is IPI software for environmental management. You can take any data logger, upload your digital data into it and automatically we'll graph it for you and also tell you when you're at risk for deterioration. It'll tell you if you're at risk for mold or chemical deterioration and all of that. And this is kind of what the graphs look like. So on the top here, we have our temperature in bold. So the darker color is the temperature. On the bottom here in the lighter red we have relative humidity. Our temperature scale is over here and a relative humidity scale is over here. And at the bottom is time. These experiments were led by Jean, excuse me, were led by Jean-Louis Bigardin, research scientist, senior research scientist here at IPI. So when I talk about this research and I say we, I really mean Jean-Louis. What he was interested in was determining temperature and moisture equilibration rates for collection materials. That is, when does the collection feel a change in environment? So data logger, so here's a data logger, was placed in the center of books in the center of stacks of paper and stacks of photographs that were both matted and unmatted. And that's how we measured kind of what the internal temperature and relative humidity was and how fast they were coming to equilibration. I just wanna say that the websites for the dew point calculator and Eclimate Notebook are also in your sort of resource handout. The photographs and papers were also housed in different enclosures such as metal edged box, museum case and a portfolio case. So we're testing out different enclosures here as well. So let's look at our first fact. Thermal equilibration is fast. That is, the collection feels a change in temperature pretty quickly. Remember that brief changes in temperature, particularly high temperatures, will not cause your collection much damage. Chemical deterioration is a really slow process. It is sustained warm temperatures that will eventually lead to chemical decay like hydrolysis. The data that's shown here is fairly representative of most collection materials. It takes no more than four to six hours for 90% equilibration. Moisture equilibration is slow. At a constant temperature, it will take a hardcover book on a shelf at least a month before the entire book has equilibrated or fully feels the change in relative humidity. A stack of matted photographs or a stack of paper in an enclosure takes about the same amount of time to reach full moisture equilibration. So here is comparison of temperature equilibration between the ambient environment and the core of a book. The red square lines are the ambient temperature and the rounded blue lines are the conditions in the center of the book. Notice the thermal equilibration is fast and reaches nearly the same temperature as the ambient with each change in temperature. So again, this red line here is our ambient and the blue line just below it is the book. So you can see that the whole book feels that change in temperature almost immediately. It's pretty fast. So I showed this a few slides ago, but it's just a reminder of the profile we used in this experiment. The change in relative humidity mirrors the change in temperature. The temperature is changing from about 20 to 30 degrees Fahrenheit and the relative humidity is changing 50 to 30%. So again, the top line in dark red is our temperature. The bottom in a lighter red is our relative humidity. It's not always going to be red. They're going to be different colors. Because moisture equilibration is slow, it takes a month or longer for a book or stack of photographs to reach 90% equilibration. So it won't surprise you that when we put the data loggers in the center of these materials, the materials didn't really fully feel the change in relative humidity during these setbacks, these changes in temperature. There isn't much to show because they really didn't feel much at all. But Jean-Louis did look at different kinds of enclosures and how they impact moisture equilibration. While temperature cycling did not have much of an impact on the relative humidity levels in the center of the stack, the enclosure type did have an impact on the micro environments in the box. So let me walk you through what's happening. So as you can see, we placed a data logger in the kind of free space within the box. And I know that when we store matted photographs or store anything, our box is just slightly larger than the materials themselves. We don't want all this free space. But for the sake of experimenting and seeing what the micro environment was happening, we needed enough space for the logger. So there it is. Over here, what we have is our graph. I want to walk you through the graph. So what's shown is the temperature and relative humidity inside the box. So remember that our ambient conditions mirror one another, temperature goes up, relative humidity goes down. The collection first feels the temperature change. And this is our dark blue line, right? This is what this logger here is experiencing as the temperature changes in the dark blue line here. And you can see that it's basically feeling what's happening, it's pretty immediate. But this lighter line, the light blue here is the moisture, right? That's the RH in the sort of moisture that the logger is experiencing what's in that micro environment. So the temperature increase first causes a really short-term desorption of the materials itself in which a small amount of moisture, a small amount of water is forced out of the material. And this is shown as a very brief and very minor increase in relative humidity inside the box. So you see the spike here, as the temperature goes up, we get this very brief spike in relative humidity as the increase in temperature is pushing water out of the materials. Then moisture diffusion takes over and controls the micro climate. That is the ambient relative humidity and time takeover. So we see the relative humidity start to drop over the period of time. Now this decrease in temperature here, right? So now the temperature is dropping. It pushes moisture into the stack, right? So the moisture is now being pushed into the materials causing a temporary decrease in relative humidity in the box. So we see this blip here. Again, the ambient relative humidity takes over. What I wanna point out that in looking at these graphs, pay close attention to the scale, right? Over here is our scale. The change in temperature is causing very brief fluxes in relative humidity. And the relative humidity change is really, really small. It's only a few percent change. Another thing to think about here is while the center of the object is not feeling much with the changes in relative humidity, the edges of the object and this print on top is likely experiencing the same conditions as the box's micro environment shown in the graph here. What is happening is that there is what's called a moisture gradient throughout the stack of photographs, books or papers. Moisture slowly diffuses through the entire object or stack, right? And so you have sort of more moisture at the top than in the middle. We're going to discuss this more later, but I just wanna introduce this idea. Jean-Louis tested several different enclosure types, right? So I showed all of those. And so here we compare the ambient relative humidity, which is the green line with the relative humidity inside a metal edge cardboard box, which is the blue line and the museum case, which is red. So notice the relative humidity changes inside the museum case, follow the same pattern as the cardboard box, but they're less extreme. And closure types do make a difference in buffering relative humidity changes. So again, we can see this blue line is our cardboard box. This is the exact same data we just looked at in the previous slide, compared with the museum case, which is kind of less extreme. So Jean-Louis repeated his tests using a more realistic profile in which there was a gradual change in temperature and relative humidity over a period of eight hours. That's the profile seen on the left. Like before, the relative humidity in each profile was adjusted to maintain constant moisture content in the space. The relative humidity profile was the mirror image of the temperature profile. The results of the data from the core of the book are on the right. As you can see, the thermal equilibration, the temperature is fast and follows the change in temperature of the ambient temperature. These are the dark lines on top. Blue is the ambient temperature. Red is the inside of the book. Moisture equilibration is slow. These are the lighter lines beneath, with the red being the relative humidity inside the book. Okay, so also notice the change in relative humidity in the center of the book actually follows the change in temperature and then gradually changing as the ambient relative humidity takes over. So, you know, in short, don't sweat the small stuff. Short-term relative humidity fluctuations are not fully experienced by the collection objects. Short-term temperature fluctuations will not last long enough to cause any chemical deterioration. During the course of this research, we also began to see a dynamic relationship exists between the temperature, the relative humidity, and the collection itself. If there is enough hygroscopic material in a closed space, the material is capable of stabilizing the relative humidity fluctuations, otherwise caused by these changes in temperature. Small quantities of moisture are absorbed or desorbed by the collection materials, responding to the temperature cycling. And this actually contributes to maintaining a steady ambient environment. So we've already seen this. The temperature changes are pushing moisture in and out of the collection. So if you remember way back in our definition of dew point, I described a phenomenon that occurs when the temperature is lowered in order to maintain better storage conditions, the relative humidity rises. And that's what's shown here. Generally, this is true. And this was the basis of our testing profile, right? That the RH is the mirror image of the temperature. However, this is actually what's observed in an empty room. So we took an empty, sealed, moisture-proof enclosure and subjected it to changes in temperature only. So what we had was a large acrylic box. We put in our temperature and humidity-controlled walk-in chamber. After the box was placed in the room, the box was sealed so that the ambient relative humidity was actually sealed inside the box. So now we have this sort of micro-environment that we've created. We then only changed the ambient temperature in the room. We use a similar test profile in which the temperature set points were changed for eight or 16 hours, which you can see here. As you can see, the relative humidity goes up as the temperature goes down as expected. The swings in relative humidity are actually significant. There's about a 14% change in relative humidity with every five-degree change in temperature. This same enclosure, which is actually imaged here, so we have a picture of our acrylic enclosure that we can seal, was filled with hygroscopic collection materials. So we have books, we have boxes that are full of photographs and paper and documents and all sorts of things. When we look at the graph, notice the swings in relative humidity are minimal. Also notice the increase in relative humidity as the temperature goes down followed by a slow decline in RH. The changes in temperature are pushing some of the moisture into and out of the collection. This water is contributing to maintaining a relatively steady relative humidity. So think of it like your freezer. We all know that the more thermal mass, the more stuff we put in our freezer, the more efficiently it runs, right? The less energy it'll take to run our freezer. So we can kind of think of our hygroscopic mass in the same way. The more hygroscopic material we have in the room, sort of the more stable our relative humidity is gonna be, it's a contributing factor. So based on this research and looking at the research by others, we developed some strategies for a sustainable approach to environmental management. We had already seen that setbacks have very little immediate impact on the collection. We felt like these were pretty good strategies, but we really wanted to test them out as well in a real situation. So spoiler alert, these are pretty good strategies and they work. So let's look at that. Many libraries do not have relative humidity control, including our university's own library. So we used our own library at the university as a test lab. And the university library was really, really gracious to allow us to sort of experiment in their collection space and in their stacks. So we implemented nightly and weekend HVAC shutdowns for a year. Our questions were, what will the collection feel and is this a good way to save energy? Our library has five zones, each of which have independent controls. And here's our chart. In zone B, here, we had no shutdowns, right? So nothing was changed. We had sort of, we had a static environment in terms of temperature. In zone D, the HVAC was turned off for up to eight hours. Similar to our other experiments, we gathered data from the ambient relative, sorry, the ambient environment, the core of various materials, and the microenvironment, so the different box types. This graph shows the ambient conditions from August to March in zones B and D. So again, no setbacks for shutdowns in B and eight-hour shutdowns in D. D is the orange line and the zone in which the shutdowns are implemented. You can see that there's blips in temperature that correspond to the shutdowns. So if you look really closely here, you know, we have these little, in red, we have these little spikes and drops in temperature. So that's when we were sort of shutting down. But you can also see that the shutdowns and no overall impact over the relative humidity. Instead, the relative humidity follows the seasonal trends. The changes in relative humidity are the same in zones D and in B. While we have seen that moisture equilibrium is slow, the collection materials will reach equilibrium with the ambient environment within a month. This graph compares the ambient relative humidity conditions in zone B where there were no shutdowns with the core of a book. The internal changes of the book follow the trends in the ambient relative humidity. It doesn't feel short-term changes, but it does fully feel sustained changes in relative humidity. This reinforces the notion that we need to pay attention to extended periods of high and low relative humidity. So we thought that perhaps if an institution did have relative humidity control, implementing a stepped seasonal profile may delay moisture equilibration of materials. We found that, what we found was that it can depend on the type of enclosure. The core of the objects in the metal edge cardboard box did reach full equilibrium, but it was delayed. The museum case in the portfolio boxes did a better job buffering the relative humidity. So in this graph here, we have this sort of stepped RH profile where with the seasons, we're stepping it up and down to be drier in the winter, more humid in the summer. The red line is our cardboard box. We can see that it actually does reach equilibrium. It's just delayed. And then here, we have our portfolio box in our museum case, and they never reach full moisture equilibrium to this higher RH. So let's move from our research lab into what we call the wild actual institutions. Some institutions are implementing these strategies for sustainable environmental control. So one of the things that Image Permanence Institute does is we actually have consulting. And so we have a couple of consultants that go out to institutions all over the country and look at the HVAC, look at the collections and help make recommendations for how to maintain a sustainable preservation environment. And so this is an institution with which we consulted. And you can see that in the beginning of the year, they were implementing a static approach, maintaining steady temperatures of about 65 degrees Fahrenheit and relative humidity of about 40 to 45%. This is a really good preservation environment. But mid-year, under our consultation, they started a dynamic approach. They implemented nightly and weekend shutdowns as well as seasonal setbacks. The storage spaces are cooler and drier in the winter, more humid in the summer and warmer, while staying within the safe limits that we discussed earlier. And this institution has reported back to us that they have major savings in their HVAC bill, in their energy bill. So this is one year's worth of data. And I have to apologize, this says one day, it should say one week. So this here is one week's worth of data from the same institution. This is from the month of June. Like our experimental data, okay, so actually what we're showing are changes in temperature, which are the shutdowns at night. So these sort of ups and downs in temperature here are shutdowns during the night. So like our experimental data, the relative humidity follows changes in temperature. The data looks a lot like the data from the self-buffering test, interesting. So as the temperature decreases, the relative humidity also decreases slightly rather than increasing due to this buffering effect by the microscopic collection material itself. Notice that the changes in relative humidity, remember scale, are very, very minimal. It's unlikely that the collection is really fully feeling or experiencing these changes in relative humidity. And these two lines are just, this particular institution has two data loggers in one space. So this is two data loggers in two different places in their storage environment. And again, this should say one week's worth of data. So we still have some unanswered questions. We know it takes a month or so for full moisture equilibration, but remember that moisture gradient? What's happening to the skin of the book? What's happening to the thing on top of the stack? We need to better understand the self-buffering phenomenon. And we're also interested to see that if an institution has no RH control, like our library, can we use the hygroscopic nature of the collection to control the relative humidity just by manipulating temperature? So the moisture gradient issue, again, the outside of the object or the thing on top of the stack feels the change in environment first. This graph shows the ambient relative humidity compared to a microenvironment in two different kinds of housings. This is an indication of what the skin of the material is actually feeling. We are currently working on a project that actually looks at the skin or the bindings of bound volumes to determine their response to changes in environmental conditions. We are interested in the rate of moisture absorption and desorption and the amount of expansion and contraction of the materials. This type of research hasn't been done on books yet because books are really complex composite objects, they're three-dimensional objects, and they're usually made with a variety of different materials and also made in a variety of different ways. All of these different materials absorb and desorb moisture at different amounts and at different rates. Because these materials are all bound together, they're also restrained, the book is restrained by itself as well as by the other books on the shelf, and this may increase the strain the book experiences as it expands and contracts. So through experience, we know that books expand and contract with changes in environment. Many of us who work in libraries have seen this expansion and contraction. Well-unbound books are particularly responsive. I've heard stories of binding splitting on books or books flying off the shelf like that scene in Ghostbusters due to changes in relative humidity. So I actually have a video here now that I wanna show. I think I need some help, Mike. How do I get the video up? Okay, the video may not work. We may have a technology fail here. Okay, no worries. I'll see if I can re-upload it. I believe you, no worries. It was working two hours ago. But essentially, we'll look at the picture first. So essentially what we have is we have these books on a shelf, right? They're laid flat just to kind of show the expansion and contraction. And this is in our walk-in chamber. The relative humidity starts at 60%. We drop it to 25% and it comes back up to 60%. As the relative humidity drops, these books respond and they actually open up. So what's happening is as the relative humidity drops, the binding, the materials contract and it kind of acts as a lever, you know, and it opens the book. And this area down below will show it sort of highlights where the areas of movement are. This was a video that was done in MATLAB by my colleague Andrew Lerwell who had kind of started this project. So yeah, so this sort of shows the book sort of opening and closing as the environment changes. So the questions that we need to answer is so what? Is the movement of the books leading to permanent deformation or are these objects actually fine? And they're just responding to changes in environment like they have been for centuries in some cases. So this book here and this book here are both vellum bound and they're pretty responsive, but they're, I think they're both like 18th century books, maybe early 19th century books. I think they might both be 18th century. So, and these books are actually in great condition. There's nothing wrong with these books. Vellum is a really strong material. So yes, we just need to find, we just need to figure out so what doesn't matter. Mike, I'm gonna move forward. So no worries if we get them to work great, if not, I probably won't cry myself to sleep. So what we're using to determine sort of what the outside of the book is feeling is a photogrammetry technique called digital image correlation. And this is to sort of study the response of the collections materials changed to relative humidity. The way digital image correlation or DIC works is we put a random dot pattern and we apply it to the surface of the test material. So here's our dot pattern, it's random. The materials are then imaged at regular intervals with two cameras which are set up in stereo and that's what is shown here. We have this sort of apparatus, a tripod with this apparatus and we have two cameras here and here which are imaging at regular intervals. It's hard to say today. These images are then run through a special software program that tracks the movement of the dots as the material expands and contracts due to water absorption and desorption and that corresponds with the changes in relative humidity. The software measures the displacement of the dots, how far they move and whether or not they actually move back to the same place. The displacement is then calculated as strain. The software gives numerical data in a spreadsheet as well as a 2D and 3D model of the object imaged. So here's actually our 2D model of these samples of parchment. So with this experiment we started off by looking at individual materials, completely unrestrained in order to get a sense of the behavior of the materials themselves before they're sort of bound and restrained. So here's several examples of 19th century parchment. These samples were exposed to three different profiles. Actually they were exposed to a total of, I think five or six different profiles, but these are three sort of desorption profiles. All of these profiles all across the board started at 50% relative humidity. So in our graph here we have one profile started at 50% relative humidity, dropped at 30% RH and then came back to 50%. The next one we did 50% to 20% to 50% and then finally 50% to 10% RH to 50%. You can see that with each 10% decrease in relative humidity, the negative strain increased. Negative strain just shows contraction of the object. So positive strain is expansion, negative strain is contraction. So it's just showing you how much it's contracted. And what we can see here is these pieces of parchment or vellum, it's the start of 0% strain and our strain levels are actually pretty significant. We get up to like 3% strain, which is kind of a lot for these materials. But when they return to 50% relative humidity, they relax and they come back more or less to square one. They come pretty close to zero. This is probably not of major concern, this tiny teeny tiny bit. These are, this is like 0.01% strain, which is not something you would ever actually see. The data can also be output as video. So here we actually have a two-dimensional video and this video is also parchment. It shows 30%, 30%, 50% profile and the color pattern of this sample indicates the amount of strain experienced by the object which is shown kind of in this scale here on the right side. What we found is that the materials initially respond really, really quickly and then there's a shoulder which moisture diffusion slows down before reaching equilibrium. We can actually see this in when it's graphed out, right? This is the response to moisture change fast. But then we kind of have this slow change as it reaches equilibrium. You can also see that although the strain is larger, thus the amount of desorption is greater as the relative humidity is decreased, then the material reaches equilibrium in the same amount of time, right? We hit this point here, the same amount of time, whether it's 30%, 20% or 10%. And this is totally expected based on what is known about moisture diffusion. This is known as Fick's law of diffusion. So regardless of the jump in change, the rate is about the same. I'm not sure if it'll work, but is it possible to bring up the second video? We're getting a security notification stopping the video as I'm going through, I'm sorry. What you'll see in this video, what you would see is that these pieces of parchment curl up. Some of them like roll up completely and I wasn't even able to get complete data off of them. But once we return to 50% relative humidity, they flatten right back out. Now, there's still a lot of research to be done here. This is, I have nothing conclusive to say other than these materials are behaving the way I expect them to behave. And I don't think 10% relative humidity is particularly good for any of these materials for a lot of reasons, but I think 30% is probably fine. So I just have a lot more to do. This is actually an experiment that's ongoing right now. I'm currently kind of in two and a half years into a three to four year project on this one. So we're actually on to the sort of second stage. We're looking at bound materials themselves and we're particularly interested in the amount of strain that happens on the spine of the book here because this is where we tend to see damage is in the spine. And this would be another video, but basically this is a well-unbound book and it shows the book as it reacts to a decrease in relative humidity. And so the relative humidity is dropping and it's doing just what the other books were doing. It's sort of opening and closing. And again, you can see that this book is actually in great condition besides the dots that I've painted all over it. And there's really nothing wrong with it, but I'm going to see if I can actually induce some damage. What is it going to take to induce damage to this book as well as other books? I have books that are cloth bound, leather bound, the Ellen bound, I have full binding, quarter bindings, half bindings, and so on and so forth. So I'm really kind of in the middle of looking at the books themselves. So I will be speaking about this at the AIC conference in Houston. So hopefully by the end of May, I'll have more to say about this data and kind of what it all means. Yeah, so kind of moving forward, the next thing we really want to explore is at low temperatures, accelerated chemical decay is not really a big concern. But again, what is a concern is the moisture content of the collection as it relates to mechanical deformation and to mold. Mold, again, will grow at low temperatures. Our next area of study, we hope, will be to determine how changes in temperature changes the moisture content of the collection. We're not as focused on how much the ambient relative humidity, like how much moisture is too much in terms of like how high the relative humidity is in the ambient room, but on how much water is in the collection and how much water in the collection is too much or too little. With this, we'll continue to explore the self-buffering phenomenon. There's a lot more research that needs to be done there. We're also interested in how to maintain constant moisture content during times of access by adjusting environmental conditions in storage areas and study rooms. So we actually have written a grant and we're waiting to hear whether or not this project will be funded. We really should hear it any day now, so fingers crossed on that. So conclusions, sorry about all the text. Short-term fluctuations are not full experience by the collection objects. Depending on your building envelope, as well as your climate, shutdowns and setbacks can save money. Again, you can shut down entirely, but if you're in Fort Lauderdale, shutting down your HVAC is probably not the best idea because it's just so humid there. But you can set it back, right? You can change your set points. This will save you a lot of money and it'll reduce your carbon footprint considerably and will do really no harm to your collection. It'll do so little harm to your collection that I made a typo and typed it twice. So there you go. Stepped seasonal RH profile may delay moisture equilibration of your materials and closures help, but when we say closures help, consider time, space and money. In managing our collections, we all know that our museum cases are more expensive and they take up more room than our metal edge cardboard box. Both are really good housings for our materials, but some are more expensive and take more space. I'm not advocating for running out and re-housing your entire collection, but moving forward, this is just something to keep in mind, especially for your really sensitive collections. And then the collections material helps to buffer relative humidity fluctuations and can actually minimize moisture content changes at the center of the object. And I think this is something that we also empirically know, but now we also know through experimentation. When I was in graduate school, one of my professors was saying, if you have a box and it's not full, put matboard in it because you want to fill up that space because again, you have this sort of hygroscopic mass that'll kind of buffer that empty space and you'll get sort of less fluctuation within the box. Your collection really isn't feeling it. So with that said, I really want to thank Connecting Two Collections Care for inviting me. This has been an awesome opportunity to share this information, to share our research. I especially want to thank the National Endowment for the Humanities Division of Preservation Access. All of the research I've just gone through was funded by the NEH. So thank you to them and thank you to you for joining me. So I think now is when I answer questions. Okay, that's right. That's right. And I just want to let you know that I will post the YouTube addresses for the videos when I post the recording. So you'll be able to get the videos. Okay, so let's start. Linda Best said, "'We lightly place plastic bags over objects on exposed shelving in the event of water from fire suppression. Is there any positive or negative impact from this practice? Is the percentage of potential deterioration from using plastic greater than the off chance of alleviation of fire suppression?" And there's quite a bit of discussion about this. So if you want to answer that question, we'll go into the discussion. Yeah, there's probably some pros and cons there. I think you're creating an additional microenvironment, which is okay. If your relative humidity gets too high, the moisture will penetrate the plastic eventually, right? I mean, plastic is not totally like a 100% barrier for moisture. So what I would be concerned about is, you want to have the right microenvironments. So by your sort of accidentally you're going to creating an extra microenvironment. So yeah, it probably will kind of add to a buffering effect. But if you have too much moisture going on, if there's too much moisture in your collection or too much moisture kind of gets in there, you might have too much water present and you might end up with pockets of mold. We see this sometimes in compact shelving, where there's not enough moisture exchange. You know, if the shelves are actually too close together, you're not getting enough moisture movement between the collections and the outside air. Moisture equilibration is a constant thing. It's not like it comes to equilibration and it's like, okay, there's equal amount of moisture in your book as there is in the air. Moisture is actually in constant motion moving in and out, right? You do have the same amount of moisture in the book in the air, but it's still moving. It doesn't like stop. And so if that moisture can't get out and it gets trapped, you might actually have a problem. So you just really need to keep aware of that. You might want to put a data logger kind of under one of your plastics just to see what that microenvironment is. So you're aware of what it is and kind of see what's going on there. That would be, you know, we advocate for, you know, when you are monitoring, leave your monitor in one space. You don't want to move it around because the point is you want a year's worth of data to see what your environment is actually doing. So you might want to get a couple of monitors just to dedicate to putting underneath that plastic shading so you know what that environment is because you just want to be careful that you're not creating the wrong environment. But yeah, I mean, that's a good question. But yeah, what's worse, right? A fire and dousing your collection with water or the microenvironment like mold could be catastrophic, but okay, I'm rambling now. That's my answer. Okay, so then Linda Ogil said, what kind of plastic are you using? And she said you may want to consider the ability for air movement, which you covered. And then there was a discussion about using leak detectors. So do you have any suggestions on using leak detectors or Sarah Dunn suggested one called Lyric Wifi Water Leak and Freezer Detector, Freeze Detector? I don't really know much about that. Yeah, about that, about the detectors. I couldn't really recommend anything specifically. It's probably not a bad idea to know that your water suppression system is leaking. That would be good to know, obviously. Yeah, but I don't have any recommendations per se. Okay, Deborah Trupin says, in your ongoing research, can you, will you also look at wood, i.e. furniture and or a gilded and gessoed objects and composite textiles? The short answer is maybe, and I hope so. So kind of the background and image permanence institute, if you can guess from the name, when we were established, our main focus was image permanence, right? So looking at mainly photographic and printed materials and the sort of preservation of those objects. And we've since expanded to sort of books and paper and other printed materials, library and archive materials. But I definitely feel like, and we've had conversations about this as a group in our lab, that we are interested and we are kind of looking to expand what kind of materials that we're looking at. I will say that other institutes look at these materials, so we kind of all have our kind of niches. We look at printed materials and photographs and books and things like that. The Getty is doing a lot of work on wood and actually looking at the mechanical behavior of wood like furniture. The Smithsonian Conservation Institute has done a lot of work with paintings. And you know, other people are looking at textiles, but I think what we really need to do as a lab is to look at whatever the people have done and see if there's any gaps or see if we can apply our research methods and what we're looking at to some of these objects. So we don't have any plans in the immediate future, but kind of looking into the future. These are the conversations that we're having. But again, we don't want to redo research that's already been done. Maybe it's just a matter of compiling the research. Okay, Rudolph Traykel says, we're adding thousands of new items to our Harvard style module at this time. How would this, I think, how would our collections that have already been acclimated in the facility for a month or more? Let's see, there's some words missing. If we test turning off the HVAC units overnight, et cetera. So how would, if you're adding materials and you have materials that are acclimated, how would that be affected by turning off the HVAC? Oh, yeah, Rudolph says, be affected. It's a really good question. You know, I'm not sure, I don't know. So we know that this sort of moisture diffusion is gonna take however long it takes, right? No matter how big that jump is. So it doesn't really matter what the environment was that where the collections were held previously. You know, when you move them into that new environment, it's gonna take how long it's gonna take for them to fully acclimate to this new space. So I guess it really depends on, if those materials were in a really dry or really humid space, you would probably want to bring them into an environment, you know, what we would determine a preservation environment, you know, somewhere in that 30 to 55% range of relative humidity. And again, with the same temperature, you know, temperature, like I said, you know, temperature does control the moisture content, right? Temperature matters and kind of let them chill there for a while before kind of moving with the rest of the collection. That might be consideration. I don't know that it would really matter that much. Honestly, like I don't think, you know, I don't want to overthink it. I don't know that it would really harm the collection. You know, there's a theory, which I think is a really valid theory by another research scientist somewhere else that kind of has, it basically says, you know, with mechanical things, you know, expansion and contraction, if your collection material has already seen 25% RH, is already seen 70% RH, like if it's already felt the extremes, when it feels those extremes again, it's not, you're not gonna do additional damage to the object. And I very much believe that's true. You know, everything we've done is pretty much pointed to that. So, you know, I don't think you're gonna harm your object by putting it into an environment that's kind of within these safe zones. You know, eventually, it's gonna have the moisture that it needs, right? It's gonna be, it's gonna be acclimated to whatever it is. I don't, you know, yeah, don't overthink it. I don't think it's that big of a deal, you know, but I'll kind of add that to my list of things to kind of check and test, you know, if we, for sure. Like, I think it's a good question. So, yeah, I'll kind of like verify, but I'm not super worried. So, I don't know, I hope that helps. Okay. Claudia Rivers says, we have experience of this phenomenon, which is things drying out and curling back in El Paso with books loan for exhibits. Since it's really dry here, some books pulled open so much that they did not fit back in the box that they were shipped in. And then, Brad Brederhoff said, you could, they need to acclimate to environmental change. And Lissa asked, do you have any suggestions for acclimating hygroscopic materials? Sure, sure you do. So, the first thing is to validate, yeah, I believe that I got a, I contributed to a dictionary on photography and it would, it was shipped to me, it was winter and the whole cover of the book was bode. And then I left it on my coffee table and by spring it had totally flattened out. And so, yeah, this is a real thing, right? The dimensions of the book will totally change depending on what the environment is. And I know in a dry environment especially, what you would have seen in that video is the books like totally open up, right? They totally sort of come open as the humidity drops. There's lots of ways that you can sort of acclimate to the environment. Again, you can create a micro environment with silica gel. You could really just get like a plastic container and put some silica gel in there and kind of put them in there. Yes, I mean, someone says don't shock them with the change. Again, with my research with my data, it's not working like that rate of change. I'm not sure how much it matters. There is, when it comes to stress and strain, basically what happens if you remember, if anybody ever played with, I'll remember, forget his name, remember that toy, stretch arms strong, right? Stretch arms strong. And you have like the big old stretchy arms. If you yank the arms really fast, they'll break off, but you had to like sort of slowly pull them. And I think that's probably what Brad is referring to with, you know, mechanical change. If you pull something really hard and really fast, you know, that it breaks. Whereas if you pull it slowly, you kind of get that stretch. But one of the things that we see is actually with a really slow drawn out change, you actually get a real alignment of the molecular structure. And so you actually get more permanent damage sometimes with really, really slow stretching and changing. So again, you know, part of this DIC project is to look at that and kind of figure out, does the rate of change matter? Does the amount of change matter? And so far, you know, our rate of change has actually been two hours. It's been pretty quickly. And I'm not actually seeing any major damage to books or to anything else, to just pieces of paper or parchment yet. So again, I don't want to say anything definitive because I'm still kind of knee deep into this project. I have a lot of analysis to do with the data, but yeah, I would just say, you know, create a microenvironment where you can bring it up. Condition silica gel is perfect. Some people use saturated salt solutions. To me, they're a hassle and they're messy. I like the silica gel. You know, you can buy the sort of condition silica gel in a box, you know, make sure that you don't accidentally like recondition it. You have to keep it in a sealed bag, mylar bag, but yeah. Okay, Amanda Shield says, how do we implement and enforce these new standards for temperature in RH? Many institutions still enforce the 70-50 rule. How do we spread this new standard to all museums and collecting institutions? You know, this information is not new. This idea of stepping away from 70-50 and having a more dynamic approach is something that we've actually been advocating for for like almost 30 years, as well as other institutions, and Smithsonian also advocates for it. The Getty also advocates for it. We've had full symposiums, international symposiums, held, you know, all over the place. There was, you know, I think there was one in Denmark, there was one held by the Smithsonian in D.C. To show different institutions' research on this, you know, just like further emphasizing and sort of further proof of the pudding, if you will, that, you know, this dynamic approach is fine, you know, and it works. It's almost frustrating to kind of be that this, you know, this sort of handful of people sort of shouting into the void, you know, to say like, no, really, you're fine. And I just think it starts with education, doing webinars like this, where we can show our research, you know, and showing proof, not don't just take my word for it, just show the data and show the proof that a dynamic and sustainable approach is fine for your collection. So it always starts with education, you know, and then I think what we need to do is we need to train the next generation of professionals. So we need this educational message to reach our educating institutions, our colleges or universities, and so that when we talk about environmental management in our conservation programs, in our museum and library science programs and, you know, our archives programs, they're talking dynamic. They're not saying 70-50. You know, 70-50 is easy. And that's why we default to it. It's easy. Like, I don't need to know what my collection is. I don't need to think about it too hard. I can just do it. But the truth is we really have to know our collections. We have to know what the materials are. We have to know how they respond to temperature. We need to know how they respond to relative humidity in order to make the best choice we can for our collection. And 70 degrees is not a good choice for most collection materials. It just isn't. It's far too warm. And, you know, and thinking about dew points is also essential. So I guess that's my answer is just education, education, education, webinars like this, you know, talking to others. And then when it comes to actually implementing it, you know, you have to think about it. You know, think about your geographical location. Again, you know, if you're in the desert or if you're somewhere really humid, you know, maybe shutting down entirely isn't the best choice, but you can do setbacks. You can change the set points. Also, you know, think about your building envelope. Can your building hold a temperature and relative humidity for a long period of time? And these are things that, you know, IPI can help you with with our consultation. A lot of institutions write grants and part of the grant is to have us come and consult. We're not the only consultation, you know, place that there is. So, you know, there's definitely other people, but you know, you can have someone come and help you make these changes. And that's kind of, you know, what generally is advocated for. But, you know, otherwise, you know, you could also just try it for a day or a week and see what happens. You're not gonna kill your collection probably in a day or a week. But I would, you know, but I would be a little more cautious and look more careful about it. Generally speaking, that's just me. I tend to be cautious. So, yeah, I hope that answers the question. Okay. Katie Hall asks, is, what's your opinion of sealed microclimates for long-term storage, i.e. Marvel seal? Oh, I love that question. Maddening place works. And we have three minutes. And three more questions. Thank you. My opinion is these sealed packages, what you're going to sort of describe them, they're also called sealed packages, are really intended for display and for travel. They often, again, the glazing is usually acrylic and it's not gonna hold. Like, it is permeable. And especially the corners of the sealed packages, we get leaks. So, your sealed package will hold for a period of time, how long I'm not sure, but eventually it'll fail. And so, you need to keep checking it, right? You need to have maybe a moisture indicator, one of those cobalt strips inside to check it. They're very expensive to make. And they take up, you know, quadruple the space of the object itself. So, you know, you might wanna be really selective of really sensitive materials if you're that worried about it. This is actually a question, this is on my list of research questions. And I'm really hoping in the next couple of years to write a grant to look at sealed packages more in depth and really to see how long do they last, what kind of, what formula, right? There's lots of ways to make these, like which one's the best. So, that's sort of earmarked for research. So, I'm glad you asked that question because it kind of reinforces my need to ask these questions. Okay. Okay. Evelyn Fiedler says, what if your collection is mixed paper, photo, furniture, tech sales, metal? Does your research applies to this collection? This is where knowing your collection comes in. You have to kind of look at the information on each of these materials and decide what your limiting factor is. What's your most sensitive material and design your environment for that? So, if you do have materials that really shouldn't be frozen, you don't want to get too cold. What you've listed are mostly hygroscopic except for metal. Metals, we can set aside. If you have a static composite object, it's just metal, drier the better, right? Metal does not like moisture. But all these other materials need to be above 30%. They need to be above 25%. They need to be 30% to 55% relative humidity. So, that might be, you might just want to err on the lower side of RH, if you can. But again, even a little bit of this stepped RH control will significantly improve your bill, right? And also reduce your carbon footprint. With that said, I was told like, well, people are mostly concerned about the money, right? The HVAC bill. Nobody really cares about the environment, but I totally disagree. I think people do care about the environment. I think people do care that not only do we have rising HVAC bills, the amount of pollutants that we're putting into the air by running our HVAC systems is significant. And so, we can do well by our planet, as well as do well by our collections. They're not mutually exclusive. So, with your mixed collections, you might want to err on the side of drier with the metals, but you can still have this dynamic approach. That was my tangent, sorry. Okay. All right. We have one more question from Jessica Lewinsky, and she says, if I have 25 data loggers distributed in my galleries, what's the best way to save the information for it to be accessible and also to be able to review the volume of data I'm acquiring and then be able to correlate? Several software programs on the market that allow you to download your data into the software and then it'll spit out the graph. And then, with most of these, you can actually compare the graphs. The only one I'm really knowledgeable about is Eclimate Notebook, because that's our software. And so, I'm just gonna talk on that because I know more about it. So, you can use any data logger. You can just download it into the program. It automatically spits out all of the data. You can compare different locations. You can compare all the different loggers. You can also kind of adjust the scales. You can look at the years worth of data. You can look at weeks worth of data. You can look at the days worth of data an hour, right? And so, and it also has what we call Preservation Metrics, which can take the guesswork out. It tells you when you're in trouble. It lets you know. Again, you always have to know your collection. If you have a room that's full of metal and it's telling you it's too dry, again, you can, you know, it's thinking, our system's thinking hygroscopic materials, you know. So you have to have like a little bit of thought into it, but mostly it really, it's a good tool that really kind of helps you manage your data and manage your environment. And once you know what your environment is, when you can spit out a whole year's worth of data, if your environment is problematic, if you are hitting those extremes, that's when you can start looking to grant funding to help you with your HVAC system and try to get it things under control. So yeah, there are other softwares out there, software programs that I'm just not as knowledgeable about, but they exist. Okay, so please fill out the evaluation. Thank you, Alice. Thank you, Mike. Everyone have wonderful holidays and we will see you in 2018. So keep looking on the website to see what's coming up. And that's it. Thank you. Bye-bye.