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1. Actively cooled server rack cabinet
2. Needs and technical solutions
3. Commercial aspects
4. About this page

 

1. Actively cooled server rack cabinet for the lower power segment

Seidl Technologies is looking for one or more partners, preferably but not necessarily from the European Union, to launch a product, which could be dealt with under the title Energetically reasonable one-cabinet data center with extremely low maintenance requirements. With such a product, we would like to fill a gap. The underlying idea is not fundamentally new. New is the focus, which is set here. As the analysis of the products of well-known manufacturers shows, there is little agreement in this regard. So we want to establish an Actively Cooled 19-inch Server Rack Cabinet in the market that is particularly suitable for small companies, medical offices, law and engineering firms, perhaps also for studios, and, that has a good price. In the case of smaller companies, the catalog of requirements with regard to such a product looks basically different from that of larger companies or data centers. In general, it is seen that, in smaller companies, it is accurately explored that an imagined procurement will advance some matter of importance and will do that for a very long time.

2. Needs and solutions from the technical point of view

It is not always right to give data and their processing out of the hands. When it really comes down to it, it is necessary that data protection is physically enforced. This in its turn requires reliable, own hardware that cannot be accessed by strangers. The opinion about what one has to understand under reliable hardware changes with time, more precisely with the technological development. What, on the other hand, seems to be relatively steady is that reliably appearing hardware comes typically in the 19-inch format. And that is first of all a good thing.

IT equipment in the 19-inch format can excellently be planned, installed and maintained. It is also undisputed that equipment in this format saves space, it is firstly stacked on top of one another and only then juxtaposed. Moreover, it is considered to be comparatively reliable, not necessarily because it works much better, but because it is usually uncompromisingly ventilated and most of the cables and connectors are protected from direct access. On the other hand, we have a number of drawbacks. Installed in office environments, 19-inch standard cabinets being full of equipment, more precisely, standard cabinets with significant energy conversion are perceived as very loud. Besides, they get polluted with time in a very unpleasant manner. Both the noise and the pollution are results of the strong and continuous gas exchange with the environment. The market takes neither the noise problem nor the dust one seriously. This is not really surprising. Well, in the huge halls of the data centers, the noise does not really matter and there is also no dust there. And since equipment, which is not intended for a data center, normally does not come to the customer in the 19-inch format, but in any cases of any size, geometry and color, and usually with a wall plug power supply, actually, there does not seem to be any reason to think about how a quiet and clean 19-inch cabinet should be built. This can be seen quite so. Furthermore, equipment encased in 19-inch standard cabinets gets quite fast unstable or dies the heat death when such a cabinet was placed in a possibly windowless broom chamber and someone has closed the door, even though the air inside there circulates well. Even a possibly existing air conditioner can only change this situation if the generated heat is actually removed from the chamber. But this is exactly that what is not done by products with a compact air conditioning unit. In addition, IT equipment in the 19-inch format costs significantly more than functionally equivalent one in a plastic or sheet metal box. And finally, there is interesting equipment that is not available in the 19-inch format at all. In spite of all the mentioned disadvantages, in 2005 we built an air-cooled cabinet, so to speak, as a first attempt, whereat it was initially not thought about its commercialization. This cabinet is still in operation today. The most important experiences and conclusions are the following ones.

  1. The massively made Cabinet in the form of a piece of furniture is completely closed except for a dust-filtered intake and an outlet opening. The walls consist of 26 mm oak wood, 12 mm cleaned bitumen, 5 mm plywood, and 3 mm neoprene, from outside to inside. Front and rear doors are screwed in place and sealed with neoprene. Vibrations of the air column in the exhaust duct are damped by means of an acoustic labyrinth. If the two openings were plugged with, for example, pillows, the sound insulation would probably be perfect. Unfortunately, the latter is not possible with air cooling, so that, with the outflowing medium, some of the noise escapes, too. The air filter in the intake duct is ⅓ m² in size so that it need not be changed or cleaned too often. Suitable filter mats are those of class F9 and of class F7 as the prefilter. At continuous fan operation, a filter change is required in the countryside every two years, and in a southern European city with a high traffic volume, one every year. An air filter that looks like this one has not been serviced for too long, whereat the photographic color contrast has been raised somewhat for clarity. The cabinet accommodates an uninterruptible power supply (UPS), three 4U rack servers, a 4U special rack chassis being full of small equipment, and a plethora of cables. Thus, the cabinet firstly fulfills its most important function. On the other hand, it is seen that we are already at this point in a position to draw conclusions of some relevance. With regard to commercialization, a cabinet in the form of a piece of furniture will likely be unaffordable and also hardly approvable. So a 19-inch standard steel cabinet seems to be the best candidate, which could also quite easily be anti-drummed by means of panels of cleaned bitumen. Further, air cooling is generally unfavorable. Neither of the two core problems, noise and dirt, can be dominated comfortably with air cooling. A commercializable layout will better work with water cooling. Therewith, the IT equipment is still cooled with air, and water as the medium serves to remove the altogether generated heat from the cabinet. With water cooling, a massive gas exchange between the cabinet and the environment need no longer happen. So, sound deadening can cost-effectively be achieved, so, the problem of getting polluted is basically no longer an issue, and so, the broom chamber situation has its natural solution. Toward the customer, water cooling is the only honest approach. He buys a product and has the real chance to be at rest for the period of a decade. This is not conceivable with air cooling in an office environment
  2. If such a cabinet is reasonably designed, it will easily reach a life of the order of 25 years. Wearing parts are firstly the fans. For models with two ball bearings, several manufacturers give 80,000 operating hours at 40°C. This lifetime will actually be achieved with high probability, since these fans are, even in the air cooling case, operated virtually dust-free, provided that the above mentioned air filter is appropriately maintained. So far, not any one of the more than 40 fans has failed. At a rough estimate, they have been cleaned once every 4 years with a paintbrush and a vacuum cleaner, whereat the respective contamination was indeed already visible in color but still harmless. As already indicated, in a cabinet with water cooling the fans need no longer be cleaned. Customers who depend on that will preventively replace fans that have 80,000 operating hours or 9 years behind them, regardless of whether these fans belong to a redundant design or not. Finally, in a water-cooled cabinet, the circulator pump will also have to be counted as a wearing part, whereat it can quite strongly be benefited from the considerable technical advances of the house technology products in recent years. A modern pump will therewith last at least a decade
  3. Unlike in a data center where practically everything runs all the time, the equipment in the application environment of our target customer group is, due to the high electrical energy prices, frequently switched on and off, and this on a per-device basis mainly governed by the day-night cycle. An online UPS according to the double-conversion principle, which itself favorably runs continuously, is very suitable for such operating habits. Firstly, the double-conversion UPS products of all well-known manufacturers are considered to be extremely reliable on their own. As well, on the condition that such a UPS is reasonably dimensioned, an advantage, which should not be underestimated, is that the components powered by it enjoy the virtually eternal life. So, each time some device with large capacitors is switched on, the UPS goes completely down into its knees for self-protection, and, in doing so, it keeps the inrush current of the powered device within relatively narrow limits. With an online UPS, the probability increases to get devices, having switched off last evening, back into operation next morning. In our cabinet, the UPS performs central functions. Consequentially, the choice of the actual type will hardly be left to the customer.
    Eligible models here are 2U or 3U high, have a power of around 1 kW and work completely autonomously, id est, without a dedicated server. They have apart from the group of the master sockets at least 2 groups of independently switchable slaves on the output side. If those slaves are missing, a separate power distribution unit (PDU) need be used, which makes the entire installation unnecessarily more expensive. Having active power factor correction (active PFC) on the input side should not be discussed anymore. Possible UPS models are equipped with a network card with temperature and humidity sensors as well as with at least 2 dry contact inputs that can be evaluated through software. So the UPS can, in the case of water cooling, via appropriately connected sensors, directly react to cooling water circuit disasters, such that it is not necessary to wait for the resulting aftereffects, namely, for the occurrence of dangerous temperatures. The network card should support status queries based on well-documented and widespread network protocols such as the SNMP with the standard UPS MIB according to RFC 1628. If this point is ignored, some trouble with the appropriate software on the servers is inevitable. Because wherefrom should a UPS manufacturer know which operating systems will run on the powered servers someday. The web server running on the network card for the administration of the UPS should support TLS-compliant encryption protocols. Furthermore, interesting UPS models have, in the best case, installed 3 or more AGM lead batteries 12 V 7 Ah of the size 151×94×65 mm³ with Faston Quick Terminals 250 (F2 (6.3 mm)). These batteries can economically be exchanged. Finally, a very crucial condition that a UPS has to meet here is that it can be turned on and off via a dry contact. As a reminder, the UPS is located in the cabinet and is thus only accessible to a limited extent. Meanwhile, there are at least two different candidates on the market, which fulfill the whole spectrum of requirements here, id est, UPS models that one can build on
  4. There are different ways to deal with several servers. In the air-cooled cabinet shown above, there are three systems, a master server, a master server cold standby, and an installation server. The master server is the workhorse, the master server cold standby is a replica of the workhorse in cold standby mode, and the installation server is a machine on which operating systems are prepared and which is always taken when a sandbox is needed in hardware. In the case of such an arrangement, two of the three systems are usually switched off. Further, there are various ways to access central resources, and such ones are the systems in our cabinet right now. If there is a demand for high safety standards or the need for limited expenditures in administration, employees access a server from their workplace via a thin client or a diskless workstation. With full confidence, a person gets the console cables installed directly to the desk. This person then has the full performance without having to accept the disadvantages which are usually associated with large machines in the immediate vicinity of the workplace. In the above case, the consoles of all servers are concentrated using a KVM switch and connected to a writing desk using extender equipment to have the 15 m long cables under control
  5. For the servers in the above air-cooled cabinet, three 19-inch rack mount enclosures of the size 4U × 700 mm were originally selected, each of which has three 120 mm fans at the internal partition panel. This type of enclosure corresponds to a full tower case lying on the side. It is therefore capable of accommodating all possible standard power supplies and mainboard formats as M-ATX, ATX, E-ATX, SSI CEB and SSI EEB, but in contrast to a full tower case, it accomplishes uncompromising ventilating conditions. The hard disks are located in the cold air area behind the two front doors with their additional air filters. The three 120 mm fans at the internal partition panel, with their key parameters 60 Pa at dV/dt=0 and 3×50 ℓ/s at Δp=0, care for pressure differences of at least 40 Pa under all circumstances of interest here, so that the takeouts at the rear panel run quasi at Δp=0. Under such conditions, a takeout of the dimension 80×80×20 mm³ at the rear panel with 7 blades of 45° slope and 3300 rpm conveys, just from its geometry, anything like 25 ℓ/s or 90 m³/h. The server enclosures in the above air-cooled cabinet have only one takeout. Two would reduce the air temperature rise to half. However, the chosen enclosure type with an electrical expenditure of significantly more than 20 W per chassis just to supply the fans is even without the second takeout hard on the limit of the tolerable. In case of a water-cooled cabinet, some things will also become more easy in this context. Resulting rack mount enclosures are first of all similar to the chassis used for servers in data centers. In the further process, the three 4U servers in the above-mentioned air-cooled cabinet were replaced in 2018 after 15 years of operation by two industrially manufactured used 2U servers. This enabled the available system performance to be multiplied in every dimension at almost constant heat dissipation. Hence there will be nothing to do for a long time on the hardware side. Each of the two servers was purchased for a good € 300 and upgraded with further € 1000. As a result, there are two machines available, each with 12 cores and support for 24 threads at a maximum of 2.67 GHz, 48 GB RAM and a logical RAID 6 hard drive of 2.4 TB. Two of the eight physical hard drives of each machine are hot standbys. In the meantime, the passively cooled graphics card for 2560x1440 at 60 Hz has been replaced by a Radeon Pro WX 5100 for 3840x2160 at 60 Hz, with the 43-inch 4K monitor connected via a hybrid DisplayPort cable made of fiber optics and copper. Unfortunately, this means that the video signals can no longer be pulled through a KVM switch. In addition, the eight quite old physical SAS hard drives of the master server, with a capacity of 600 GB each, were replaced by eight used PM1635a 960 GB solid-state drives for a total price of € 800, so that the I/O performance has now grown to an appropriate level. There is USB 3.0 for hard drive backup, also via a hybrid cable. Of course, as expected, well-programmed USB 2.0 devices have no problems with such hybrid USB 3.0 cables, too. USB 3.0 is also good for external sound cards. Some USB 2.0 sound cards do not work properly on USB 2.0 because they try to draw too much electrical current. The servers have been designed by the manufacturer for warm data centers. They have regulated fans and can be operated at air temperatures in the range from 10°C to 35°C. The presence of a console processor is also advantageous. As usual, installing the latest firmware requires some experience, but since the systems represent widespread, well-documented hardware of a famous manufacturer, one does not face serious problems. The same applies in principle to the procurement of spare parts. Figure Two systems x3650 M3 from the front shows below a system as it was delivered at some point in time for a good € 300 and above that a system after its upgrade. One can see that above the optical drive is missing and the hard drives moved to the drive bay in the middle. In the left drive bay, the hard drives on the left became impermissibly hot, even when the enclosure was operated in the free space outside the cabinet. Why the latter is the case becomes clear relatively quickly by taking a Look at an open x3650 M3 system from the top. One last figure, Two systems x3650 M3 from behind, completes the overview of the servers. It should be mentioned that Reverse Flow Blockers can practically only be mounted on the front side when using industrial servers
  6. The mentioned special rack chassis allows to accommodate small non-19-inch devices such as routers, switches, media converters, KVM hardware, private automatic branch exchanges, parts of video surveillance devices, et cetera, together with their many wall plug power supplies, and, it allows to operate them under extremely favorable conditions. Even Wi-Fi access points can be hidden away in this manner, if only their antenna cables are routed out of the cabinet again. In this context, the experiences speak a clear language. Small devices, which have found their place in the special rack chassis, do not show the slightest instability. For that matter, the actual ambient temperature is largely insignificant. The point is the permanent ventilation such that temperature hotspots are avoided. Without such a special rack chassis, the envisaged target customer group will hardly be enthusiastic about a 19-inch cabinet. Only if a cabinet succeeds to absorb virtually the entire portfolio of available IT equipment in an expedient and discreet manner, then it fulfills its purpose here. As already denoted, expedient means in this case not only to house IT equipment, but also to ventilate it well and dust-free. The special rack chassis needs to be dextrously designed. It was found that the height of 4U is not enough. On the other hand, a height of 8U appears optimally. This chassis must be accessible from the front and from the rear without having to be pulled out. It must be sensibly divided, must offer numerous possibilities to fix the small devices and their cables, and must provide many mains sockets at a sufficient distance from one another. It makes little sense to mount the special rack chassis movably in the cabinet. The large number of cables, which finally enter or exit at the rear side, is likely to prevent at the end any movement of the chassis. Lastly, just to complete the understanding. Hardware that requires operator interventions, as for example printers, can neither have a place in the special rack chassis nor in the cabinet at all. Similarly, such things as ADSL modems should also not be dragged into the cabinet. It is safer to have a purely optical connection between a far away modem and the cabinet, in order to keep the overvoltage problem under control
  7. The height of 18U provided by the air-cooled cabinet shown above is too small. So it is quite unpleasant, if, in addition to some job to put a new machine into the cabinet, respecting time requirements, and to set it into operation, the decision has to be made, which of the previously installed servers has to be forever dispensed with. It is much more comfortable to have both things decoupled from each other. In this context, 42U, for example, offer a luxury of quite another kind. In addition to the customarily used hardware, there is a lot of space that could serve, on the one hand, to hold retired servers as standby systems, data storage or sandboxes available, and, on the other hand, to store unused units in a space-saving manner, and that at least as long until it is clarified that they are actually no longer needed
  8. As already indicated, it is assumed that, due to the high electrical energy prices, the target customer group being in our focus switches the equipment on and off on a per-device basis, mainly governed by the day-night cycle. This creates another problem. Thus, if no action is taken, units that are switched on can overheat because the cooling air can partially flow back through units being switched off such that a running unit does not exclusively get cold air at the inlet, but a mixture of cold air and its own exhaust air. Depending on the instantaneous flow conditions, dangerous temperature increases can occur that way with disastrous consequences. Although the air-cooled variant shown above may be more susceptible to this effect than a water-cooled variant, it is in both cases necessary to provide a remedy. The technological solution here is to install the already mentioned Reverse Flow Blockers. In data center environments, this issue plays a subordinate role

Let us take into account all points touched. Our new cabinet, whose commercialization is intended, will be designed to provide a safe and unobtrusive home for almost everything of remotely controllable equipment being available in the IT market, to allow the housed equipment operating under favorable conditions, to run, apart from due UPS battery changes every three to five years, maintenance-free for something like a decade, to represent an energetically reasonable solution, to have a generally accepted price, and to enjoy itself a very long life. A complete package consisting of four apparently separable components wants to be delivered.

Actively cooled server rack cabinet

Three of these four components are schematically shown in the above illustration. On the left we see the cabinet. It could be a symmetrical 19-inch standard cabinet, made from steel, with closed doors in the front and rear and the dimensions 42U × 600×1200 mm². The spacing between the front and rear mounting posts should be 800 mm. IP 54 is planned as the degree of protection. An optional anti-drumming kit should be offered to improve sound absorption. In the cabinet, the 8U air-water heat exchanger is located below. Above it there is the pump casing. On the right side of the illustration we have the water recooler. In our case, this is not a recooler with a chiller, that is a recooler with a machine performing thermodynamic cycles, but a common warm water convector radiator for living quarters, indeed a model of relatively high power. The third visible component is the tubing. With ½-inch armored hose, there is a pressure drop of approximately 0.3 bar at 5 ℓ/min volume flow rate and 40 m length. In approximation, the pressure drop increases with the square of the volume flow rate and linearly with the length. For further orientation, the water temperature rise is little less than 3 K at 5 ℓ/min volume flow rate and 1 kW total dissipation power. The fourth and last component, a small control device, is not represented in the illustration.

It can be seen what should happen here. The problem case, the standard server rack cabinet with its characteristics large, loud, heat and dust sensitive is smashed into two parts, which can more easily be controlled. A water-cooled server rack cabinet can be placed practically everywhere, in particular into the mentioned dark broom chamber, whose door could be specially secured for this purpose. Within the cabinet, comparatively high air volume flow rates can be realized to care for smallest air temperature rises. Concerning the space consumption, practically nothing changes. The cabinet will be aligned with one of its side panels towards a wall. Before and behind the cabinet, the necessary maneuvering space must, now like before, be reserved, which, however, can be occupied by easily movable objects since the experience shows that a server rack cabinet need be opened less frequently than once a year. With 21U for servers and storage, there is quite an amount of space available such that different concepts can be considered. One point is thereby, of course, that everything can be switched on and off from the outside. The warm water radiator will, on the other hand, be installed where it is most appropriate. It makes no noise and heats the room which it is in. It should therefore not be covered.

There will be several questions. A first is surely the one of the reason why a warm water radiator should be used here instead of a water recooler with a chiller, or, again, instead of a water recooler with a machine performing thermodynamic cycles. For the intended solution, two circumstances speak first of all. Firstly, it would be very difficult to communicate to our target customer group that there is a need for a device, weighing 30 to 70 kg and put-putting permanently or intermittently around, to properly operate some servers that should replace the up to now somehow put up computers of a customer. And where, if necessary, should such a device find its place in an office, perhaps in the kitchenette? Secondly, in a data center with its enormous power densities, there is hardly any other way than to spend one more amount of electrical energy for cooling that is almost of the same order of magnitude as the one being used to supply the equipment itself. The recoolers used there are at the same time much more efficient than any 1 kW model. In addition, data centers as large consumers are relatively favorably tariffed, whereas the final result of the German energy policy for the consumer is a kilowatt-hour price for electrical energy around ⅓ €. One consequence is that a usual tower case computer installed in an office must not consume more electrical energy for its cooling than that for a few fans. The same rule should basically be applied to the servers in our cabinet, too. Such an argument speaks even more against a water recooler with a chiller. In addition, the situation can be seen from a completely different angle. IT equipment transforms electrical energy into heat. In many parts of the world, this heat can almost all the year round be used to heat the rooms, which means that the electrical energy is used to turn bits in the processors as well as to move bytes, and, on the other hand, to heat the house. So the balance is better than is commonly assumed, but of course only with the warm water radiator. In other parts of the world with perhaps 45°C outside temperature, IT equipment can normally not be operated without the support of refrigeration machines. But also in these areas, it can be sensible to get rid of the heat through a warm water radiator directly to the office, which is often cooled down to 18°C. It is thus possible to dispose of the heat without great circumstances via the building air-conditioning system. So there is something that speaks for the warm water radiator with its two great advantages, not making noise and being almost maintenance free. Nevertheless, we will design the air-water heat exchanger in such a way that condensate drainage is perfectly mastered, too, so that the cabinet can also be operated with a recooler with a refrigeration machine. Those customers who want to cool in this manner will, of course, abdicate the pump casing over the air-water heat exchanger.

Further questions arise. Probably the most important point is to find out under what conditions the whole installation really works. For that we apply a method called Design of Experiments with its brute-force variant Full Factorial Design, whereat the experiments are replaced by computer simulations. Results obtained in this way can be illustrated in a special graph. First of all, however, is to be clarified what is calculated. The cold air flow indicated on the left in the above illustration is uniformly distributed over a very large number of imaginary, identical rack mount drawer units of infinitesimal height. A first, binary influencing factor determines whether the cold air flow is only distributed over the units being switched on, or over all the units, where a maximum of 1013 of all units can be switched on. The air volume flow inside the units being switched on is selected via a further, binary influencing factor such that the air temperature rise equals either 3.3 K or twice that value. The volumetric flow rate through the units being switched off is, as long as it differs from zero, the same as the one through the units being switched on. The air, emerging from the units on the right, gets mixed and yields the warm air. The calculations concerning the air-water heat exchanger are controlled by means of two further influencing factors. A first, again binary one determines whether the quotient of the temperature difference between cold air and cold water for cocurrent flow and the same temperature difference for countercurrent flow should equal 1.82 or 1.42 . The air-water heat exchanger itself is, of course, operated countercurrently. The second, ternary influencing factor determines the contact surface of the air-water heat exchanger. The latter can be 2A, 3A, or 4A, where A is slightly more than 5m². A further influencing factor determines the volume flow rate of the cooling water, 150, 300, or 600 ℓ/h. Finally, a last, ternary influencing factor determines the nominal power of the warm water radiator. This can equal 3, 6, or 12 kW. The following graph shows the most important results.

Actively cooled server rack cabinet - Design of experiments 2

Shown is the very important difference between the temperature of the air, exiting one of the switched-on rack mount drawer units on the right, and the ambient temperature at the installation location of the warm water radiator, and this temperature difference above the overall consumed electrical power being transformed into a heat flow rate out of the cabinet. Parameters are the mentioned influencing factors. For the maximum permissible value of the temperature on the output side of a switched-on rack mount drawer unit, we take the value of 40°C, which was once given by Intel for the maximum permissible operating temperature of mainboards. This value is not irrefutable, but it coincides with long lasting experiences with consumer-level products made by different manufacturers. In short, up to 40°C board temperature, there is not the slightest complaint in terms of stability when using ECC memory. Further, the offices of Seidl Technologies, as an example, have south-facing windows and are not air-conditioned. Therefore, the temperature there can just rise once to 30°C in summer. If one of these offices is now also the location of the warm water radiator, then all permissible operating conditions of the installation can directly be read out. Thus, at 30°C, everything below the horizontal 10 K line is allowed. Correspondingly, at 28°C maximum office temperature, everything would be allowed that was below the horizontal line at 12 K. We come to explain the influencing factors. Obviously, the curves in magenta (Magenta rectangle), in brown (Brown rectangle), and in cyan (Cyan rectangle) belong to 6.6 K air temperature rise within a switched-on rack mount drawer unit, while the curves in red (Red rectangle), in green (Green rectangle), and in blue (Blue rectangle) belong to 3.3 K. On the other hand, the curves in magenta (Magenta rectangle) and in red (Red rectangle) belong to 3 kW nominal warm water radiator heat power, the curves in brown (Brown rectangle) and in green (Green rectangle) to 6 kW, and the curves in cyan (Cyan rectangle) and in blue (Blue rectangle) to 2×6 kW. As a reminder, the nominal warm water radiator heat power here refers to the EN442 standard conditions 75°C / 65°C / 20°C, and a radiator exponent of 43 has been assumed. As expected, the nominal warm water radiator heat power dominates the situation. Besides, the air temperature rise in the rack mount drawer units should be kept at values of about 3 K. With the comparatively low power densities here, this is not a problem at all. Seen from the point of view of the approach, working on one of the green lines is favored, id est, with a single warm water radiator as described above. Hence, ambient temperatures of 30°C still allow 400 W power consumption in the cabinet, those of 28°C already 600 W, and those of 23°C the full kilowatt. In certain circumstances, the warm water radiator can be placed in a larger stairwell or basement, such that outsiders do not get access to it, or, if the space conditions permit that, two 6 kW models can too be connected in series. With two 6 kW models in series, even 800 W are still possible at 30°C in the environment. It should also be mentioned that the air-water heat exchanger should possess a certain minimum value with regard to its heat capacity to cushion impacts caused by cooling water circuit disasters. It should further be noted that temporal temperature changes should not exceed a rate of 20 K/h as long as massive hard disk accesses occur. Of course, this last condition can also most easily be fulfilled with two 6 kW models in series.

3. Commercial aspects

There is no doubt that there are customers for the solution presented. The problems are everywhere the same and to rely on the 19-inch format is as consequent as reasonable. What the experience, however, quite clearly shows is that, outside of data centers, the usability of 19-inch data center equipment is rather limited, and that 19-inch equipment, which is intended for customers outside of data centers, does not meet the needs the envisaged target customer group really has. Against such a backdrop, we want to offer an energetically reasonable one-cabinet data center with extremely low maintenance requirements, and we want to have commercial success with it. Such a one-cabinet data center is therefore certainly not a product for which the components can easily be gathered together. Such a one-cabinet data center is a product consisting of different, partly multiply existing components, of which at least six have to be specially manufactured here. These six components, which have to be specially manufactured, are the air-water heat exchanger, the pump casing, the mentioned Reverse Flow Blockers, the special rack chassis, the small control device, and the optional anti-drumming kit to improve sound absorption. Of course, as in the case of the air-cooled variant, the devil is also in the detail here. Two prototypes should soon be built. This requires funds that Seidl Technologies alone does not have. When it comes to prototype construction, our aim is not only to ensure that the design of the components to be manufactured turns out suitable and cost-effective, but also to permit the separate marketability of at least the air-water heat exchanger, the special rack chassis, and the Reverse Flow Blockers. Perhaps even the pump casing is salable if it is offered together with air-water heat exchanger, one will see. For the special rack chassis, also data centers are seen as a target customer group if they are going to eliminate their messy corners. Finally, the competitors, too, which at the moment are, of course, not yet existing, could be considered as a target customer group for all the components to be manufactured.

In summary, our main objective here is to find a highly productive metal construction company with certain qualifications in the electronic and electrical engineering sector, which has the will and the strength to tackle the outlined project together with us. How the cooperation in this case actually turns out will surely be subject of negotiations. Alternatively, if you think that we have a good thing on here, there is always the possibility to push the prototyping through direct financial contributions. Just contact us.

A solid way to prepare contacts with us is the one via the Customer data form. Please forgive the circumstance that it is still seen that this form was originally only intended to prepare business relations with customers. As a potential partner you will surely expand the part Cooperation in this form.

4. About this page

This page has been online since January the 9th, 2017.

The present release of this page is the version 4 of October the 12th, 2024.

   
             
   

   
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