What is immersion liquid (“dry water”) and where is it used?

This material will be devoted to the topic of cooling mining farms using the immersion method. Another name for this process is water cooling or immersion liquid cooling by using a substance called “dry water”.

Overheating of a mining farm can lead to many negative aspects, including decreased operating efficiency, unstable data, increased wear and tear, and even complete shutdown of the farm due to high temperature. That is why cooling is now the most pressing issue for owners of mining farms.

If the mining rig operates at a power of 5 to 15 kW, then you can cope with the overheating of such a device on your own. For example, opening windows, adding air conditioners to the room, moving equipment to an open space and other tricks that users use help.

But, if the farm is of an industrial scale, it is quite difficult to create conditions that limit overheating. As a rule, such sets of devices have powers of up to 500 kW and even MW.

We want to introduce a new product to the market - a cooling system for mining farms, running on immersion liquid, which will help maintain the operation of the installation even at high power levels and avoid carrying out independent cooling measures.

Main characteristics and scope of application of immersion liquid

Immersion cooling is carried out by lowering the equipment into a container of “dry water”. Thus, it turns out that heat is removed from the farm.

Immersion liquid or “dry water” is a proprietary technical type liquid created with a specific formula. Due to the manufacturing technology, the finished substance is endowed with the following positive qualities:

• non-flammability;
• inertia;
• low toxicity;
• high dielectric properties.

The last criterion allows the use of such a liquid in combination with any electrical equipment, since it will not enter into a chemical reaction with any substance.

Important! The use of immersion liquid is completely safe, both for the equipment and for those people who work with it.

The use of this substance on an industrial scale is a long-standing process. And now it does not lose its relevance. “Dry water” is mainly used for cooling measures in data centers and in fire extinguishing systems at facilities where a fire can lead to irreparable loss. For example, in the archive of important documentation.

Typically, during the construction of a data center, most of the budget goes to installing the cooling system. During operation, cooling also requires constant financial investments, which amount to about 50% of all monthly expenses. As the amount of data that needs digital storage is constantly growing, the cost of cooling equipment is also rising. This leads to the fact that owners are forced to look for technologies that will be most beneficial for them.

Since liquid cooling is highly efficient compared to other technologies, it is being used more and more often. This is also facilitated by the cost-effectiveness of the technology from a financial point of view. Immersion liquid cooling is suitable for any equipment, including ASIC miners such as Antminer S9, L3+, D3 and NVIDIA Geforce 1070 GTX, 1060 GTX, AMD Radeon RX 470, 480, 580 and others.

Additional room ventilation

Even video cards with an ideal cooling system will overheat in a closed room without ventilation, especially if it’s hot outside. What can you do?

Fans

Buy a floor fan, it can lower the temperature of the farm by 5/6 degrees.

Attention! You need to install the fan so that it blows the cards from the end, or from the backplate. By directing a strong air stream directly at the video card propeller, you can break it. It's good if there is an open door on the opposite side. The heat will immediately evaporate without accumulating in the room. A household fan should be designed for large areas, but it's probably not worth paying extra for the extra bells and whistles and design. However, let everyone decide for themselves. And don’t forget to clean the device from dust at least once a month. A mining farm also requires maintenance. Stores sell cans of compressed air to remove dust from computer components, but it is better to purchase an electric blower.

For a mini-farm, you can buy a table fan. It costs less and consumes less electricity, but it cools less and breaks down more often. However, in some cases this is the most suitable option.

Air conditioner

A drastic measure for additional cooling of video cards is to install an air conditioner. An expensive, if not wasteful, option. Please note that the split system is designed to work indoors, and the mining farm seriously heats the air. It's like turning on an air conditioner and an electric heater at the same time. You will pay a lot for electricity, and the air conditioner will fail prematurely. In addition, the house must have reliable electrical wiring, otherwise a fire will occur.

Hoods

A farm hood is designed to remove residual heat from a room. Not a single data center can operate without forced ventilation, but the advisability of using it at home is questionable.

The device is noisy and energy-intensive, and is not cheap. It’s easier to open the window, creating a draft. By the way, the farm not only heats, but also dries the air. It would be a good idea to install a humidifier or an open container of water in one room (but away from the farm). The most exotic method is to empty containers of dry ice, but this is an expensive proposition.

Features of the liquid cooling system

Operating “dry water” is a simple process that even a beginner in this matter can understand. Since the solution is completely safe for equipment, a working mining rig is immersed in it. During operation, the equipment releases thermal energy, which becomes an impetus for heating the liquid. Using physics, we can say that the heat capacity of a liquid is 400 times less than the same unit for air. This allows heat to be removed with a much smaller coolant volume.

The main task of liquid cooling is high-quality heat removal from the solution itself and maintaining a comfortable temperature of the mining farm, which will allow the equipment to operate without complaints and failures with maximum efficiency.

Rice. 1 – Option for operating an electrical device in a cooling liquid

Liquid cooling of a mining farm under experimental conditions

Initial experiments in the laboratory are always very exciting, especially if an expensive operating system is immersed in a liquid. Any person knows that electricity and liquid are two different and completely incompatible things. And such a discovery as the operation of a device inside a solution is a real breakthrough in science.

At the moment, many companies in the world are developing formulas and producing immersion liquid, which, in addition to cooling, can perform other related tasks.

Here is an experiment with a mining farm carried out by laboratory specialists:

The tests were carried out in order to identify the best composition to increase the efficiency of heat transfer, which gives precisely high thermophysical properties.

The experiment is carried out on a sample bench-type mining farm. The device consists of 6 Nvidia Geforce GTX 1070 video cards. The total power of such a device is 1.2 kW. The liquid was cooled using a conventional cold water supply system.

At the first stage, the equipment was completely immersed in a container with liquid. For better cooling, water circulation was created using a pumping unit. The experiment took several days, during which various operating modes were tried.

Rice. 2 – An example of an Nvidia Geforce video card operating in an immersion liquid

Here are the results obtained by laboratory specialists:

1. The equipment operated stably and as efficiently as possible throughout the experiment.
2. When changing parameters, the performance of video cards increased by 15% on average. But there are suggestions that this figure is not the limit.
3. When regulating the cooling system, it was possible to set a cooling mode that minimized the cost of cold water consumption.
4. No fans were used during the experiment.

Such results of the experiment are amazing and are direct evidence that cooling mining farms using immersion liquid is an excellent solution.

Water-cooled ASIC Bitmain Antminer C1

Technical characteristics of Bitmain Antminer C1

Miner connection

To get started with Bitmain Antminer C1, you need to take the following steps:

1. We connect the ASIC and PC using a network cable.
2. We indicate the IP address of the device (192.168.1.99) in the browser line, and in this way we log in to the system. The username and password at the time of login (by default) is root.
3. Change the IP address through the settings menu. Now click on Network and select save and apply.

Setting and status

1. Pool URL.
   Here you need to register the address of the pool with which you plan to work.
2. Login and password.
   These fields contain the employee data specified during registration in the bulletin. Please note that one ASIC miner can be configured to work with three pools simultaneously. In this case, the pools have different priorities. If working with the first one does not bring profit, the second one is connected and so on.
3. "Beeper ringing"
   If you check the box, the device notifies you that cryptocurrency mining has stopped.
4. Temperature limitation.
   When setting the settings, you can set the miner to stop when the temperature reaches 80 degrees Celsius. If this is not done, it will continue to work, but then there is a risk of the device overheating and failure.
5. Saving settings.
   After this, you need to restart the miner, after which it starts mining cryptocurrency.

Profitability

In conclusion, let’s calculate the profit of the water-cooled Bitmain Antminer C1 miner as of 02/14/2018. Information for calculation:

1. Hashrate - 1 TH/sec.
2. Cryptocurrency - Bitcoin.
3. The rate is $8,794 for 1 Bitcoin.
4. The block reward is 12.5 BTC coins.
5. Power consumption - 820 W.
6. Electricity tariff is $0.09.
7. The period of work is 30 days.

Positive features of immersion cooling in the mining process

Based on facts, experience in using immersion liquid in various industries for many years, user reviews, laboratory tests and manufacturer guarantees, we can highlight a lot of advantages that the substance has:

1. Increased equipment efficiency by 15%. Here everything depends only on the characteristics of the devices themselves that are installed on the mining farm. Different models have their own characteristics and limitations. But if you approach the matter wisely and maintain the temperature between 40 and 50 degrees, it is not difficult to achieve even greater results.
2. Increasing the service life of devices. If the temperature of the mining equipment is always at a comfortable level, then the devices do not overheat. And this, accordingly, leads to an increase in service life and the elimination of shutdowns due to overheating.
3. Quiet operation. Miners immersed in liquid operate as quietly as possible. This is achieved by completely turning off the fans and the air cooling system, which in operation produces a sound almost comparable to that coming from the ventilation of an industrial workshop.
4. Compactness. So, for example, a container with dimensions of 1.5 * 1.5 m contains an amount of equipment with a total power of approximately 20 - 30 kW. It follows from this that a large farm with a power of 100 kW will fit on an area of ​​5 - 10 square meters. meters.
5. Reducing the cost of purchasing video cards. Since liquid cooling does not involve the use of coolers, you can order completely bare chips. They don't even need a body. The cost of such a video card will be 30% lower. And its dimensions will be significantly reduced, which will allow the farm to be arranged more densely.

Types of video card cooling

When choosing graphics adapters for mining, pay attention to the cooler. Devices with one propeller and cheap models without heat pipes are not worth buying. Not to mention video cards without forced cooling. However, the most budget GPUs are absolutely unsuitable for mining due to their low computing power. Of course, during the crypto fever, farms were even assembled from Rx 560/550. But then they paid for themselves faster than they failed. Turbine-cooled cards are noisier and run hotter.

The best option would be two or three fan GPU devices. Modern video cards are designed for high loads, but it is still difficult for them to mine cryptocurrency 24/7. It is necessary to take into account the features of a particular model.

Some GPUs, for example, the GTX 1080 Ti, operate comfortably at 72/75C, but for the Rx 570 this is a lot, their operating temperature is 60/63C. Of course, overheating by 2-3 degrees will not lead to immediate failure. But the equipment will produce a lot of broken balls, freeze, and the hash rate will drop. As a result, you will lose money. Therefore, if the temperature in mining is higher than normal, additional cooling is necessary for the video card.

Additional coolers

Craftsmen place large PC fans opposite each video card, or on both sides, to provide powerful airflow.

The option is not bad in principle, but it is quite expensive and increases the noise level. In addition, additional coolers load the power supply of the farm, and if the power supply is not enough, the system will reboot or shut down completely.

Thermal paste

The quality of the thermal paste also plays a role. Thermal paste is a mineral mixture made according to a special recipe, characterized by high heat-conducting properties. In consistency, it resembles toothpaste or shoe polish. The substance is applied to the protective cover of the video chip and then air heat sinks are installed on top. The paste fills all the unevenness and roughness of the surface of both the cooler grille and the GPU cover, ensuring maximum heat transfer.

During operation, the mixture gradually dries out and loses its properties. But even on new video cards, the thermal interface is not always ideal. When a device sits on a store shelf for a long time, the thermal paste gradually ages, and sometimes a manufacturing defect occurs. If the video card is still under warranty, you cannot change the thermal paste yourself; you need to go to a service center.

In principle, replacing a thermal interface is not a difficult task, however, if you have never done this, contact a specialist. Due to inexperience, you can even “kill” the graphics processor. In addition, it is very important to choose the right mixture. Good thermal pastes are produced by Arctic.

Liquid and air cooling: comparison of techniques

To better understand immersion liquid cooling technology, it is compared with similar air cooling. Those positive properties that were mentioned earlier are the advantages that distinguish liquid cooling.

It can be noted that air cooling also has its own characteristics, which in no way detract from its advantages. Air can also provide effective cooling, which will allow the system to operate smoothly. Although in the summer months this cooling option is more difficult to perform than a similar liquid one.

Within the framework of this material, it would be wrong not to talk about the disadvantages that immersion cooling has:

1. Complexity in calculations, which only a specialist can do.
2. A small number of those specialists who really understand the topic.
3. Difficulty in purchasing the required liquid.
4. High price.

The last indicator is subjective, since the price of liquid cooling, if configured correctly, will be comparable to the same air cooling system. And if you take into account all the advantages of the system, you can understand that the payback will be quick.

It is difficult to create a mining rig with immersion cooling on your own, so now there are many options for ready-made devices. So, for example, the PLAST.RU company creates and installs turnkey immersion mining farms. These farms are distinguished by high quality characteristics that will delight their owner and give him an impetus to increase profitability from this activity. You just need to order a mining device, and PLAST.RU will do the rest.

The conclusion is that evidence has shown that immersion cooling is a modern and energy-efficient technique that is increasingly being used for mining.

Flaws

Like any technical design, immersion cooling has a set of disadvantages, in particular:

• High price. The thing is that maintenance of such a structure can cost at least 25% of the cost of maintaining the farm as a whole. That is, if an installed farm consumes energy worth 10,000 rubles. Then the cooling costs will be 2,500 rubles. Coolant is not cheap.
• The container for immersion liquid opens only from the top and therefore it is unlikely to be possible to assemble the farm on racks.
• When carrying out preventive maintenance, liquid may get on the floor, and it is difficult to wipe it off.
• It is necessary to ensure filtering of the working fluid. This will avoid the formation of sediment and contamination.

Options for using heat from mining farms

The energy consumed by equipment is predominantly converted into thermal energy. With a high power mining rig, a huge amount of heat is generated, and it would be wrong to miss this fact. Thus, the generated heat can be used for both domestic and industrial purposes. We will give some examples:

1. Heating a body of water, for example a swimming pool. In this case, a water heat exchanger is used, transferring heat from the internal to the external circuit, which allows you to obtain warm water at the outlet.
2. Heating the room. This could be a room, an office, a whole workshop, or even a greenhouse. In this case, the internal liquid circuit is cooled by passing through a water-air heat exchanger. And hot air can be used for those purposes that were previously planned.
3. Installation of heated floors indoors. To organize such a system, a water-to-water heat exchanger is used. The liquid turns out warm and the floor is heated.

It is important to calculate all of the listed methods of using heat in advance so that they fit the existing conditions and meet the requirements. It is difficult to give any universal solution for each option.

In conclusion, I would like to say that immersion cooling of mining farms is an advanced process in the field of IT technology, which undoubtedly deserves attention.