Free Siberian style
Once in a small Siberian university there was a small server room for 10 racks and ~ 20 kW of total power consumption. Day and night, the rest and the temperature regime were guarded by two big brothers Leonardo, each with 20 kW of heat. But it just so happened that the dwarves who monitored the condition of the brothers were very lazy - in the three years of “serving” one of the brothers became very bad and spent most of the time on sick leave. When a healer of air conditioners was called in, a terrible assumption was confirmed - the brothers needed a major overhaul, up to the possible replacement of units. Repair this expensive, threatening to result in an amount of up to 1 million rubles. for every air conditioner, and besides requiring serious downtime for the entire server, of course, was not part of anyone’s plans. It was decided to treat the brothers.
Tenders, contests, contracts ... and now half a year has passed, and the second brother began to leave.
In parallel, the staff began to look for ways to reduce the load on the remaining air conditioner. So for a while the floor-mounted air conditioner was merely 5 kW, using a technical hole in the wall as exhaust. He saved a small air conditioner in the hot summer months, but during the same time he tried to drown the server room in his condensate twice. Later with the onset of winter, when the air conditioner was already returned to the owner, it turned out that the same technical hole with a diameter of 20 cm due to the thrust generated by exhaust ventilation, with a frost of -25 ..- 30C is equivalent to an air conditioner of 5-10 kW. And at this very moment, someone uttered the overseas word "free-cooling", which he heard recently at a technical fair. We rushed to look for technology on smart books - and indeed, there is such a technology that uses air from the atmosphere to cool it. With what, with what, but with the cold air of the atmosphere in Siberia everything is fine. After some hesitation, the project “Siberian freekuling” was born:
Used materials:
While the radio-electrician assembles the control unit, the units are mounted according to a very simple scheme: radiators are installed 2 each in metal frames and are connected in parallel in the unit; one unit is installed indoors, the second - on the street; The blocks are interconnected by metal-plastic pipes with the installation of a circulation pump on one of them.
View near:
Connection diagram and coolant flow:
After assembly, the system is checked for tightness, filled with antifreeze "under the lid" and wrapped with a net so that the playful little hands to the fans do not climb.
The assembled control unit is installed on the wall and electrical circuits are switched.
The control unit is divided into several parts:
Test run - the cold has gone!
For half an hour of the system operation, the server has cooled down to the long-seemed fiction + 18C.
The design power of the system at -15 ..- 20C outside and +18 .. + 20C inside should be 50 kW. In this case, the system itself consumes a maximum of 1.5-2.0 kW. If the temperature on the street rises to 0 .. + 5C, it will be possible to turn on the second or third speed at the circulating pump, and at that time you see, and large air conditioners will repair without stopping the server.
Upd (07.03) or Epilogue: The last 4 days were on pins and needles - the remaining air conditioner began to refuse.
It happened on Saturday late in the evening. Around midnight, the air conditioner was restarted and he began to cool the server quietly. Already during the day we realized that the pump protection had worked on the free-cooling (the same ill-fated 18 degrees of antifreeze) and the fans of the indoor unit had been driving air through warm radiators for half a day. The defense was reconfigured and free-cooling began to work in full force already at the third speed of the pump.
Around 10 pm on Sunday, the air conditioner was re-chopped off, but the night was cold, for 8 hours (at 6 am it was started) the server room heated from + 19C to + 29C cooled only by free cooling! And judging by the schedule, the temperature would be set somewhere at +30 .. + 35C - a lot, but not enough for the servers to become disconnected due to protection.
The remaining two nights even had to be left on duty to monitor the temperature and, if necessary, he restarted the air conditioner. The matter was complicated by the fact that spring had already arrived on the street and the effectiveness of free cooling began to decline. At the same time, a specialist was called from an office engaged in the repair of our air conditioners, so that he could rebuild and launch the already repaired air conditioner. We must pay tribute to him, because on the third day he succeeded in this and since Wednesday evening he has been working without any problems. Also on Wednesday, I managed to correct errors in the web interface of the Carel WebGate device and it turned from a monitoring device into an air conditioner control device, so now if problems arise they can be solved remotely. Now we are waiting for the repair of the second air conditioner, but that's another story.
Tenders, contests, contracts ... and now half a year has passed, and the second brother began to leave.
In parallel, the staff began to look for ways to reduce the load on the remaining air conditioner. So for a while the floor-mounted air conditioner was merely 5 kW, using a technical hole in the wall as exhaust. He saved a small air conditioner in the hot summer months, but during the same time he tried to drown the server room in his condensate twice. Later with the onset of winter, when the air conditioner was already returned to the owner, it turned out that the same technical hole with a diameter of 20 cm due to the thrust generated by exhaust ventilation, with a frost of -25 ..- 30C is equivalent to an air conditioner of 5-10 kW. And at this very moment, someone uttered the overseas word "free-cooling", which he heard recently at a technical fair. We rushed to look for technology on smart books - and indeed, there is such a technology that uses air from the atmosphere to cool it. With what, with what, but with the cold air of the atmosphere in Siberia everything is fine. After some hesitation, the project “Siberian freekuling” was born:
Used materials:
- Circulation pump - 1 pc.
- Pipes metalplastic section
104 cm - 20 meters - Rubber pipes
104 cm - 5 meters - Automobile radiator with a set of fans - 4 pcs.
- Antifreeze - 15-20 liters
- Smart radio mechanic with a set of radio components - 1 pc.
- Metal frame - 2 pcs.
- clamps, protective mesh, etc.
While the radio-electrician assembles the control unit, the units are mounted according to a very simple scheme: radiators are installed 2 each in metal frames and are connected in parallel in the unit; one unit is installed indoors, the second - on the street; The blocks are interconnected by metal-plastic pipes with the installation of a circulation pump on one of them.
View near:
Connection diagram and coolant flow:
After assembly, the system is checked for tightness, filled with antifreeze "under the lid" and wrapped with a net so that the playful little hands to the fans do not climb.
The assembled control unit is installed on the wall and electrical circuits are switched.
The control unit is divided into several parts:
- The scheme keeping the coolant temperature at the entrance from the street in the range of +3 .. + 5.5C using 8 speeds of rotation of the fans on the outdoor unit
- Scheme regulating the temperature in the room using 4 speeds of rotation of the fans of the indoor unit
- Protection of the circulation pump from idle operation
Test run - the cold has gone!
For half an hour of the system operation, the server has cooled down to the long-seemed fiction + 18C.
The design power of the system at -15 ..- 20C outside and +18 .. + 20C inside should be 50 kW. In this case, the system itself consumes a maximum of 1.5-2.0 kW. If the temperature on the street rises to 0 .. + 5C, it will be possible to turn on the second or third speed at the circulating pump, and at that time you see, and large air conditioners will repair without stopping the server.
Upd (07.03) or Epilogue: The last 4 days were on pins and needles - the remaining air conditioner began to refuse.
It happened on Saturday late in the evening. Around midnight, the air conditioner was restarted and he began to cool the server quietly. Already during the day we realized that the pump protection had worked on the free-cooling (the same ill-fated 18 degrees of antifreeze) and the fans of the indoor unit had been driving air through warm radiators for half a day. The defense was reconfigured and free-cooling began to work in full force already at the third speed of the pump.
Around 10 pm on Sunday, the air conditioner was re-chopped off, but the night was cold, for 8 hours (at 6 am it was started) the server room heated from + 19C to + 29C cooled only by free cooling! And judging by the schedule, the temperature would be set somewhere at +30 .. + 35C - a lot, but not enough for the servers to become disconnected due to protection.
The remaining two nights even had to be left on duty to monitor the temperature and, if necessary, he restarted the air conditioner. The matter was complicated by the fact that spring had already arrived on the street and the effectiveness of free cooling began to decline. At the same time, a specialist was called from an office engaged in the repair of our air conditioners, so that he could rebuild and launch the already repaired air conditioner. We must pay tribute to him, because on the third day he succeeded in this and since Wednesday evening he has been working without any problems. Also on Wednesday, I managed to correct errors in the web interface of the Carel WebGate device and it turned from a monitoring device into an air conditioner control device, so now if problems arise they can be solved remotely. Now we are waiting for the repair of the second air conditioner, but that's another story.
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Source: https://habr.com/ru/post/138898/
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