Cable Management and PUE: How are they connected?

In the last article, our company talked about the principles of working with cables, which we adhere to for many years. This time we offer to talk about how effective cable management can affect the PUE data center. The effect is only positive. If everything is done correctly, then PUE will only decrease.

We ourselves have long been convinced that a well-thought-out infrastructure with rational cable placement can effectively affect the PUE data center. This may seem strange, but the cables, the cooling of the north and, accordingly, the PUE coefficient are quite strongly connected. How? Let's talk about this.

So, inefficient cable management leads to the fact that the direction of the air flow changes inside the data center and between its individual elements. These changes lead to a deterioration in the cooling efficiency of the data center. In this case, the cooling system operates in the same mode. But the power of the cooling system is not enough to create the same microclimate conditions. Equipment is heated, energy costs are rising. Accordingly, the PUE coefficient increases, and the data center operator in vain loses time and money for the operation of cooling systems.
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Sometimes the chaotic placement of cables can lead to the emergence of particularly heated zones, which is fraught with equipment failure. To solve this problem, data center operators usually prefer to increase the speed of the air flow in the data center and lower the operating temperature of the cooling systems. All this leads to unnecessary costs and beats the company's budget. And all because when laying cables, few people think about how to pass cold air through the cables that occur to him along the way. And you need to think, because in this case the data center may face not only an increase in PUE, but also a failure of the equipment, if the cooling is insufficient.

In the data center, attention should be paid to the following methods of laying cables: laying cables under the raised floor, passing cables to the grid, laying cables in construction and above the stand. The list may not be complete. So if you have your own options, indicate them in the comments.

Cable Management and Raised Floor

Placing cables under the raised floor
Cables can and should be placed under the raised floor. The main problem is that cables can block the path of cold air. And this, in turn, can affect the level of statistical pressure under the raised floor. A situation arises when the cooling efficiency, previously the former is quite acceptable, decreases.

What can be done?
Try to place cable trays as high as possible so that air can pass under them;
In order to avoid the influence of wires on the currents of cool air, it is necessary to place cable trays in hot corridors. Only in this case the wires will not affect the efficiency of the cooling system;
If the cable is not used, remove it, do not leave unnecessary items.

Laying cables through the raised floor grille
In this situation, the cooling system works in vain, because the cold air is blocked, the wires prevent the cooling of special equipment. The more cables inserted in the raised floor, the higher the PUE. However, many data center operators prefer to run wires through a raised floor. In this case, there is almost no cool air here, and it is necessary to increase the activity of the fans and the cooling system as a whole.



What can be done?
Cable openings for racks that do not close should be closed;
Also, experts recommend to remove all excess holes under the power equipment;
It is worth replacing all perforated raised floor plates with plates without perforation.

Cable management and server racks
Almost all data center operators seek to increase the density of servers located inside the rack. The tighter the equipment placement inside the mounting racks, the more power and network cables are in the rack. Accordingly, the greater the likelihood of overheating of the equipment. Everything is logical.

When chaotic placement of cables inside the server rack air can be blocked and not pass through the rack. This will lead to an accumulation of hot air in its back. Here the dependence is simple - the more cables, the greater the problems with the cooling system. Increases the load on the cooling system, free cooling can be used less time.

What can be done?
Use deep and wide server racks with additional tools for cable management;
The deeper the cabinet, the greater the volume of air passes in a vertical plane, without any problems in the form of obstacles;
We also recommend using blank panels. This is true when increasing the number of cables that increase the pressure inside the case;
Never need to block the channel exhaust air from the servers.

Cable management over the rack
The simple operation of moving the cable trays closer to the ceiling from under the raised floor helps increase air distribution efficiency. As a result, the efficiency of air distribution in the enterprise will be increased.

What can be done?
No need to install cable trays high above racks;
If neither hot nor cold corridors, you should try special insulation sheaths for cable trays.

As output: as you can see, cable management is receiving more and more attention. This is correct, since this area is no less important than the density of equipment, the microclimate in DC, and so on. If the cables are not placed correctly, it can negatively affect not only the efficiency of the cooling equipment, energy will be consumed more, PUE will grow.