#4【冷凍庫PC】一時結露対策と、次にできそうな対策 FreezerPC


In this video, I will introduce the effects of dew condensation measures taken on the freezer PC and ideas on dew condensation measures that I are considering in the future. First of all. Let’s start with a brief overview of this video. About effect of measures. When the temperature was changed from -30 ° C in the frozen state to 20 ° C at room temperature, the humidity inside the freezer PC reproducing # 1 and # 2 reached a maximum of 92% RH. It was also confirmed that frost and dew had formed. On the other hand, based on the countermeasures introduced in # 3 and the comments received, four dew condensation countermeasures resulted in a maximum humidity of 30% RH. And frost and dew could not be confirmed anymore. I was very surprised personally because the effect was so obvious. Details will be introduced later, but at the moment I think that I have taken enough dew condensation measures for experimental operation. Next time, I think it seems that I can confirm the operation of Intel genuine air cooling cooler with peace of mind. About future dew condensation measures. Based on the advice in the comments I received, I came up with two ideas for anti-condensation that could be purchased, made and managed by myself in the future. Production of dry air using a compressor and construction of a chamber that can seal dry air under high pressure. I consider these two plans as the best I can do. By the way, this video introduces the concept of the idea and comments based on the idea. However, I will not introduce details such as how to realize it or specific plans. However, if the two proposals can be realized, it will be possible to prevent dew condensation more stably for a long time, that is, to build a cooling system with improved regular use. That is all for the overview. Well, it looks like this, and the thumbnail of the video probably reflects my feelings like that. However, this is a measure to make it harder for dew condensation, so the possibility of failure due to dew condensation does not disappear. In addition, the measures introduced here may have overlooked disadvantages that have not yet been noticed. In such a case, I will deal with them one by one after I understand the situation. As mentioned in the overview, the main content of this video is the physical phenomenon of condensation. Sorry for those who want to see the PC operation and benchmark using the low temperature of the freezer. Next time is a video of PC operation. When I was thinking about this dew condensation measure, I wasn’t reluctant because I wanted to run a PC soon. However, when I was actually making it, it looked like a custom motorcycle electrical component and it was fun. In addition, I was delighted to see the effects of the measures and ideas. Above all, I realized that dew condensation was an important factor for PC operation in a low temperature environment, so I made a this video. This video looks like this. Let’s get started! First of all, it is about the dew condensation measures actually taken this time. By the way, I actually implemented the countermeasures and confirmed the effect. However, since it was important to determine whether or not dew condensation would occur, I focused on factors that might be related to dew condensation. In other words, cables such as ATX24pin were installed in a condition that assumed actual operation, and a heat sink of an Intel retail cooler was installed in the freezer as an observation target to check whether condensation would occur. On the other hand, almost all PC parts, which are unlikely to be a direct cause of condensation, were taken out of the freezer. I did not need to make observations on PC parts that are vulnerable to dew condensation such as M / B, and thought that heat sinks, which use more metal materials than M / B, are more likely to condense and are suitable for observation. Although it could not be reproduced exactly, I decided that it would be possible to determine the effectiveness of dew condensation measures without M / B. So I first performed a reproduction experiment to see how dew condensation occurred in the conventional structures # 1 and # 2. However, it is not strictly the state like # 1. It has been dismantled once for water cooling replacement, and the type of cable used has also been changed. The thermocouple cable used to measure the temperature in the freezer has been changed to a measuring instrument cable that can simultaneously monitor temperature and humidity. It is a great thermo-hygrometer suitable for this application, which can be purchased for about 7 $, operated by a coin battery and the display and the measuring unit are separate. Well, the original is for pet supplies, so I can’t expect high measurement accuracy. However, compared to the six thermo-hygrometers in my house, such as the thermo-hygrometer I already bought, the temperature was within ± 1 ° C and the humidity was within ± 5% RH, so it seems to be usable enough. The LED power cable was not attached for some reason. I don’t remember why I didn’t put it on now, but after all I’m testing without it. Installed in the freezer are the aluminum frame for fixing the M / B, the measuring section of the thermo-hygrometer introduced earlier, and the thermo-hygrometer that I used before. Then, a heat sink made of a metal material, which is more susceptible to dew condensation because the temperature is less likely to change than air, was also installed as an observation target. As I mentioned earlier, the heatsink was on the Intel retail cooler, so it was easy to separate the fan from the heatsink. So this time, I sacrifice this heat sink for condensation. By the way, the way of assembling the aluminum frame installed in the freezer was also changed. In the past, the aluminum frame that fixed the M / B and cable was of an integral structure, but has been improved to match the water-cooled replacement. The fixation of the self-made lid and the filling of the gap in the cable penetration part reproduced the previous method. The lid was fixed at four corners with curing tape, and curing tape was used to fill gaps in the cable penetrations. Looking from the observation window, it looks like this. Until now, observation windows were sparsely considered to be weak points in both insulation and airtightness, This time it was a great help. It was good to be able to see. In this state, use the quick freezing function to cool down to the maximum. Five hours after the start of freezing, the freezer became stable at -32 ° C. The humidity at this time is 20% RH. Here, turn off the freezer and change the temperature from the frozen state to room temperature assuming maintenance. When freezing, I used the included lid on top of self-made lid to improve the heat insulation, but when I returned the freezer temperature to room temperature, I removed the included lid and made self-made lid Had only been. It would be harder for dew condensation to occur if the temperature change in the freezer is moderate, so it seems better to put the lids on top of each other. However, this time, I wanted to observe the inside, so I removed the included lid. After a while, ice crystals were formed in the observation window. Since it is an ice crystal formed in the observation window, it has nothing to do with PC parts, but when it comes to water, a terrible existence that could cause a PC failure appeared easily. I’m scared. Let’s look inside. The wall inside the freezer is white and seems to have frost. The heat sink also has a lot of frost, but the more serious is the aluminum frame. It’s frosty enough to be easily understood. Interestingly, the upper part of the aluminum frame seems to have more frost. It seems that the aluminum frame could not cope with the temperature change of the air, and it got frosted. However, since the air warmed from the upper part in the freezer, the upper part tends to be frosted, and the lower part seems to have less frost. I took a video of the thermo-hygrometer inside the freezer for about 6 hours and checked the changes in temperature and humidity. By the way, it is a movie shooting to check the temperature and humidity for a long time. It is not a data logger or a device that records measured values. In other words, the previous graph data is based on a data log created manually by looking at the captured video at a fast-forward. The graph contains human error elements in addition to the measurement accuracy of the measuring instrument because of human input. Well, the accuracy may be fine because it is a personal posted video, but I took data in a stupid way. There are some data loggers that I want, but if they are new, they cost over $ 1000 and used ones cost over $ 500. So give up now, hoping to buy it someday. No, what is it that I want to buy a measuring instrument that is more expensive than the total amount of experimental PC parts …? Well, I’m doing something weird now. Here are the changes in temperature and humidity that I could get. As temperature increases, so does humidity. Above 0 ° C the frost melted and turned into water. It is strange to think that dew is formed from water that has melted frost, but in any case, it was confirmed that water adhered to the installation in the freezer. In fact, it was a little surprising personally. In # 3, it was explained that by repeatedly changing the temperature in the freezer, the amount of water in the freezer gradually increases. What was surprising, however, was that once a frozen environment of -30 ° C was created, dew condensation was at a level that could be visually confirmed. Cooling down to -10 ° C or -30 ° C will reduce the volume of air in the freezer by the amount of cooling, and will increase the amount of moisture as outside air enters. I also wondered how the temperature difference between air and metal parts, which is considered to be one of the factors related to dew condensation, also affected how much the temperature inside the freezer was cooled. The greater the temperature to be changed, the wider the temperature difference between air and metal will be. To summarize what I learned from this experiment, it is said that “PCs should not be cooled in the freezer.” It’s still more, but I was able to experience something strange in terms of physical phenomena. This is the end of the current status check, and the next is the introduction of the dew condensation measures implemented this time and the effect check. First, let’s review the six measures proposed in the previous video. (1) To improve the tightness of the freezer lid so that the humid air outside the freezer does not enter the freezer, stick the outer circumference of the freezer and the self-made lid around with aluminum tape. (2) Use the putty used in air conditioner installation work to fill gaps in the cable penetrations such as ATX24pin. (3) and (4) In order to reduce water vapor in the air, which is the cause of dew condensation, introduce a moisture absorber using silica gel or a dehumidifier using a peltier device. (5) In order to eliminate the situation where PC parts are cooler than air, perform high-load operations such as stress tests on PCs and heat them up to the temperature range just before dew condensation occurs. (6) In the temperature range where dew condensation occurs, shut down the PC and turn off the power of the PC power supply itself to reduce the risk of short circuit even if dew condensation occurs. I was thinking about these six countermeasures. The measures actually implemented this time refer to the advice given in the comments and are changed when they are implemented. First, about a moisture absorber using silica gel. A calcium chloride treatment layer has been added with reference to the comments received. Originally, the concept of a moisture absorber using silica gel was to use a moisture-absorbing material that could be reused many times, but due to the principle of silica gel moisture absorption, it does not seem to absorb moisture below the freezing point. Calcium chloride, on the other hand, is a component used as a type of hygroscopic material that changes from solid to liquid when it absorbs moisture. This phenomenon is a deliquescence that occurs with sodium hydroxide and can be used below freezing. Although it is disposable, I decided to use it with silica gel. I also refer to the website where DIY moisture absorber was made. Air circulation was achieved using aquarium equipment, and airtightness was maintained using containers such as tappers and air conditioning putty. When the tube on the intake side is closed, the inside of the tapper containing the air pump becomes low pressure, and it is sealed to the point that it gradually dents. With such a simple structure, a low-pressure closed container such as a vacuum chamber can be easily made. The dehumidifier using the peltier device was assembled normally, but it is perforated so that it can be fixed to the aluminum frame and metal fittings are attached. It was my first time using a Peltier device, so I checked the operation after assembling it. What was useful here was the device used to check the operation of the motorcycle’s electrical components. Although it is composed of three devices, it can be used in the same way as a commercially available power supply. Using this, I checked the operation of the Peltier device and decided to supply it by supplying roughly 7.5V. I also thought that the dehumidifier using the Peltier device would work separately from the PC power supply, so I actually supplied power with these devices. In addition to the dehumidifier using the peltier device, a fan for air circulation was installed based on the comments received. The method of using a fan for this air circulation has the same mechanism as the dehumidifying function in the M / B used. When I looked at the BIOS of my Asrock Z170 Extreme6, I noticed that it was there but forgot it. When I remembered and looked at the contents of the function, it was the same mechanism as the comment that I received, in that the fan was turned regularly even in the shutdown state to circulate the air inside the case. At first it was adopted with the idea that it would be effective if done by Asrock, but by circulating air, it will create convection and reduce the temperature difference between air and metal parts and suppress condensation. Convection air will also evaporate water from condensation. The fan was installed under the M / B so that wind could flow on both sides of the M / B. In order to move the air circulation by this fan separately from the PC power supply, the wiring of the fan was modified. Together with the power line of the peltier device, it was connected with the connector purchased for the motorcycle, and the power cable was wired from the freezer to the outside. What I was doing was the same as my motorcycle electrical component custom. At first, I was depressed because I was worried whether the anti-condensation measures were effective, but it was fun when I was doing this wiring work. After that, the air tube and the power cable for the dehumidifier were integrated with the cable such as USB and installed in the cable penetration. It can be installed much easier than before. Also, it seems easy to add cables and expandability has increased. Rather, it is a strange sight that the air tube is wired together with the cable such as USB. The idea of using aluminum tape to attach the outer periphery of the lid was changed to curing tape. After all, it was troublesome to use aluminum tape. Putting tape on the outer periphery of the lid and closing the gap between the cable penetrations is a simple task. However, because of the large amount of work, I changed to a curing tape with good workability. Putty filling of the cable penetration was carried out as planned. Although it was a sudden introduction of practice, it was easy to implement and I think that the appearance has been beautifully closed. Well, I don’t expect the effect to completely prevent the invasion of air even if I fill in with putty. To prevent air intrusion, a structure like a sealed chamber such as an O-ring will be required. The airtightness of the cable penetration part by filling with putty is like a cushioning material that delays the ingress of air. By the way, I improved the way of assembling the aluminum frame to fix the PC parts when taking this measure. In the previous structure, wire nets and aluminum frames hindered taping. So I improved the assembly and made a work space near the cable penetration. Thanks to this, taping and putty filling can be done normally. Perhaps the previous structure was a difficult task. For the time being, I was able to close it tightly without any gaps. I did not try the other measures, such as heat generation by PC parts itself and shutdown, because no PC parts were installed this time. Let’s look at the effects of these measures. First, dehumidify the air in the freezer before freezing using a moisture absorber using silica gel and calcium chloride. At the start of moisture absorption, the temperature was close to 23 ° C and the humidity was close to 60% RH. Eventually, the temperature inside the freezer was about 23 ° C, and the humidity could be reduced to below 20% RH. But it took 12 hours … It takes too long. Well, it doesn’t matter if it takes twelve hours, it’s still experimental and I can wait. Also, the work of cooling from room temperature to a frozen state is rarely done. … But it’s long. For now, I were able to dehumidify the air in the freezer in advance, so I will start freezing from here. The moisture absorber is operated even during freezing. Five hours after the start of freezing, the freezer temperature was stabilized at -30 ° C and the humidity was stabilized at about 23% RH. Even after stopping the air circulation by the moisture absorber and closing the air tube, the temperature did not decrease thereafter. It seems that the temperature changed to about 2 ℃ due to the structure change. Is it the effect of combining cables such as USB into one, or the effect of adding air tubes, power cables, and wiring? Or is it the effect of changing the measurement position of the thermo-hygrometer? There are many factors so let’s go through. It’s not fatal and I’re going to change the structure in the future, so that’s it. Let’s take a look at the calcium chloride and silica gel of the moisture absorber that worked so far. Calcium chloride is stuck together in grains. It seems that moisture has absorbed and deliquescent, and the grains have stuck together. Silica gel did not change. When moisture is absorbed, the blue grains turn pink, but remain blue. The structure of the moisture absorber this time circulated air in the order of a calcium chloride absorption tank, an air pump, and a silica gel absorption tank, but maybe it was a waste to absorb moisture first with calcium chloride. Calcium chloride cannot be reused. The next time I use it, I think it should be a structure that circulates air in the order of silica gel moisture tank, calcium chloride moisture tank, and air pump. Let’s return to the normal temperature from the frozen state assuming maintenance. From here, in addition to the moisture absorber, the dehumidifier using the peltier device and the fan for air circulation in the freezer were operated. However, after trying to return to room temperature and driving the moisture absorber, I left the freezer running for two hours. I began to question that the temperature did not rise, and stopped freezing after I noticed it. There was such a mistake, but the obtained result is the temperature and humidity change graph at the beginning of this video. And it took 4 hours to return the freezer to room temperature. If the refrigeration function was stopped from the beginning, it would return to room temperature within 3 hours. In addition, it was explained that the moisture was dehumidified by the heat absorption of the peltier device, but the peltier device also generates heat. It generates heat and generates more heat than it absorbs heat, so the whole device works like a heater. It seems that the air in the freezer was warmed up quickly. On the other hand, the temperature difference between the air and the metal parts is likely to increase, making it easier for frost and dew to form, but the temperature difference could have been reduced by the presence of a fan for air circulation. The measures were introduced for different purposes but seem to be helping each other. The humidifier may not have been very effective because it takes time for the moisture absorption effect to appear. Was it better than not moving? I think that. As a result, almost no frost was seen in the freezer, and only the frost was on the heat sink on the heat absorbing surface of the Peltier device. The peltier device seems to be collecting water vapor in the air as intended. No frost can be seen on the wall inside the freezer, the aluminum frame, or the heat sink to be observed. Is it so different! I was surprised to see the wall inside the freezer. I am glad that the effect was more than expected, but on the other hand, the result was too good to identify the problem and I did not understand the phenomenon, so is this really OK? On the contrary, I was worried. After 4 hours of running the dehumidifier, the temperature inside the freezer was higher than room temperature. This is because the peltier device continued to heat up as a heater, so even if I take things out of the freezer, I do not have to worry about condensation from the air outside the freezer. With the measures implemented this time, I decided that it would be possible to ignore the effects of condensation for experimental operation. In confirming the effects of this measure, I did not confirm the effects of condensation when freezing for a long time or changing the temperature of the air in the freezer by benchmarking with a PC in the freezer. However, at present, I consider it to be an experimental stage until the antifreeze liquid cooling is completed. For now, once I’ve done some benchmarking and other operations, I’re going to take this dew condensation countermeasure overnight. After the antifreeze liquid cooling is completed, I will make major structural changes. I also have the delusion that adding dew condensation measures, which will be introduced later, will help reduce dew condensation more efficiently. This is the end of the confirmation of the effect of the dew condensation measures implemented this time. Maybe the video time is longer. I’m sorry, the content is still half. I did not want to talk about dew condensation again if I split the video into two, so I will end the topic of dew condensation this time. From here on, I will introduce future dew condensation measures. First of all, thank you for watching and commenting on the video # 3. As the content of # 3 was a matter of dew condensation, I received a lot of advice, and I was able to add options that I could not imagine. Therefore, I will introduce some advices that are excerpted and summarized in 4 items, and the measures against dew condensation in the future. First, comments on dew point temperature. When I first received this related comment, it was only a bit of my understanding. In the first place, dew condensation was related to the amount of saturated water vapor and temperature, and was probably an understanding at a high school knowledge level. However, when I investigated dew point temperature and dew condensation again, I was able to link it to the thermodynamic knowledge I learned at college. Speaking of details is omitted because the study elements of mathematics and physics become too strong. However, I was able to quantitatively think about phenomena such as why water is produced by using a compressor. Now that I understand the principle, it will be easier to explain the effectiveness of anti-condensation measures in the future, and it will be possible to consider how much I can make at the DIY level. It was an advice that gave me a new perspective… It was very helpful…. Next is the comment on “Let’s dry the air.” It is advised to introduce chemicals such as quicklime and calcium chloride and machines such as dehumidifiers and compressors. Calcium chloride was used this time, but I are considering a dehumidifier and a compressor in the future. Using a compressor can dry the air more than usual. Maybe I could dry the air at 20 ° C and humidity of 20% RH 8 times created by this measure, and if the temperature is 20 ° C, it could be 2% humidity. At this stage it’s like a delusion. And now, I am producing dry air using a compressor, which I am expecting, but I initially foresaw it as a countermeasure against condensation. I do not know the principle and mechanism of making dry air with a compressor, so I can not do DIY, and commercial products are expensive, thousands to tens of thousands of dollars. However, I posted # 3 and changed my mind in two weeks. At the moment, if you introduce it as a personal DIY, it seems that I can build a system for about 100 to 200 $. In the first place, the structure of the freezer PC itself will be changed drastically, and the high airtightness of the container is also considered. The cost is about 100 to 200 $ in addition to the compressor, after the remodeling cost of the structural change. On the other hand, including the results of the anti-condensation measures implemented this time, the compressor may be excessive, and a dehumidifier may be sufficient. So, for now, it is positioned as the top measure to be taken if the dehumidifier is not enough. However, in future improvements to the equipment, I decided to design with expandability and equipment structure based on the introduction of compressors. For the moment, there is a personal disadvantage to introducing a compressor. I can only imagine how to use it to create dry air and fly trash. Nevertheless, I’m concerned that the compressor I’m considering purchasing is so big that it might get in the way. Sound and vibration can be managed somehow, but in the future it is likely that the need and disadvantages of a compressor will be balanced. In any case, thanks to this advice, I have once again added the option of installing a compressor. The third comment is to make a container around the freezer and dehumidify the air inside the container. If this idea is used as it is, there is waste heat from the freezer, so it is necessary to take measures against waste heat. However, it seems to be effective as a dew condensation countermeasure, and above all my DIY ability can be realized immediately. This is a great idea. The mechanism is as follows (1) to (5). (1) Freeze the freezer or move the PC. (2) The temperature of the air in the freezer changes. (3) The volume changes, and air flows in and out. (4) Make dehumidified air outside the freezer in advance. (5) Dehumidified air reduces the risk of condensation. As a result, it is expected that the risk of dew condensation in long-term operation, which was not considered in this measure, can be stably suppressed. In terms of the goal of a freezer PC, “It can be cooled and used regularly”, it seems to contribute to regular use. Finally, there is the comment “Let’s remove the air in the first place”. There were gases such as N2 and CO2, oil immersion, liquid immersion, and vacuum. By the way, the most helpful advice personally is vacuum. Oil immersion and liquid immersion are not considered at this time. Sorry, I’m reluctant to adopt this approach. I was thinking of replacing the gas in the freezer with N2 and CO2. However, it was troublesome to purchase a gas source and it was difficult to make a container to hold the gas, so I had to give it off. At present, I have come to the point of view of dry air from compressors, so I are not thinking much about gas measures. But whether it is compressor or gas, which is easier to install, build, maintain, etc., which is more effective, which one does not take up more space, etc. I’m gonna think about it. Maybe my heart has changed over time. It is a comment to make a vacuum like a semantic work, but from here I got an important idea. By the way, if a vacuum is applied, the exhaust heat of the PC parts cannot escape to the air, so there will be no condensation but cooling will not be possible. However, I was able to come up with the idea that water can be dissipated instead of air. Recently, in addition to CPU and Gravo, M / B, memory and M.2 SSD are also water cooled. Even if the vacuum was applied, it seemed that the waste heat could be treated by water cooling. Well, I don’t know what happens to the PC parts if it’s actually vacuumed, and it’s a technically difficult option. So it’s a peculiar idea. But I personally thought it was an important idea. Perhaps it will reappear at the final stage of the freezer PC. These advices are likely to significantly affect future dew condensation measures and equipment structure. The following are dew condensation measures to be considered in the future. (1) Double the container and fill it with air dried with a dehumidifier or compressor. (2) Improve the airtightness of the container itself, and maintain the pressurized state when introducing a compressor. I will consider these two concepts. Some of the comments I received were similar to the ideas I have for the future cooling system structure. When I considered the introduction of gas cooling, I thought that the current structure would not be able to cope with it, so it will likely undergo a major structural change. However, I think there are various devices and technologies that must be realized even if the structure is changed. It’s like I’m still at the beginning of a long journey, building up one by one. So, even if I talk about the concept now, the feasibility is too unclear, so I will introduce it again as the schedule approaches. In the near future, I plan to make and play with the concept of what to do with the structure of the freezer PC in the future. I would like to be able to easily introduce it again on that occasion. This concludes our discussion of dew condensation measures. That’s it for this video. Thank you for watching for a long time. Next time I will run the PC! , So I packed the topic of condensation into a single video. But most of what I wanted to talk about was a long video. That’s why I did something like a gross job as a posted video that showed the graph results at the beginning of the video. Well, there will be no chance to make such a physical experiment video like this. Rather, I hope that it does not happen. Either way, it’s fun to be able to plan, progress, and publish any personally posted video. I hope you watch the next video.Thank you for watching so long! Goodbye!

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