Information technology consumes increasing amounts of energy, and therefore energy efficiency is of increasing importance in both economic and ecological terms. Since a major element of energy costs falls to climate control, one of the most important areas of focus for improving energy efficiency is in this area. Now a colocation and solution provider for telecommunications is offering cold aisle containment to customers of its colocation spaces in Frankfurt that provide better energy efficiency than the traditional arrangement of cabinets.

Frankfurt-based NewTelco GmbH is a neutral solution provider for telecommunications transmission systems. Its major customers are large and smaller network operators who operate their own networks or also use external networks. The company's extensive range of services runs from simply offering spaces for racks through port leasing to complete solutions. NewTelco's core business is providing and operating fully equipped colocation centres in various locations worldwide, developing solutions and supplying hardware, along with qualified and fast-acting support round the clock. The company was established in 2005 and has since grown into a provider of services to international clients. With its market niche and strategic partnerships with leading manufacturers, the company has succeeded in creating a new type of telecommunications service.

Improving efficiency in the customer's interest

NewTelco operates several colocation centres in Frankfurt (Germany), Johannesburg (South Africa) and Kiev (Ukraine) and a further 14 rented spaces in other countries. A new colocation centre is currently being built in Georgia. At the Frankfurt site (Rebstöckerstrasse 25-31/Kleyerstrasse 90) the company is now running its first two cold aisle containment sections. The conventional arrangement of cabinets in rows in an air-conditioned room has had to be rethought on the basis of better energy efficiency.

By arranging the cabinets into cold and hot aisles, the efficiency improvements gained through this configuration can be further increased by placing these aisles within so-called containment. When deciding whether to opt for hot or cold aisle containment, or a combination of both, the existing local conditions play a significant part. Cold aisle containment is simple to create in rooms that already have room air conditioning.

Flexible hardware for the infrastructure

Since 2006 NewTelco has collaborated with the cabinet and enclosure manufacturer Schroff of Straubenhardt in procuring the hardware required for its colocation centres. The racks for the various locations are chosen from the flexible Varistar cabinet platform from Schroff. This consists of a frame available in two versions, various cladding parts and an extensive programme of expansion and accessory components. The "Slim-Line" version of the cabinet is suitable for lower static loads. Where a higher static load-carrying capacity or earthquake resistance is required, the second frame type is selected. This, the 'Heavy-Duty' version, consists of the same hollow-chamber profile, but which here has been extended in the main load direction to offer a still higher degree of robustness. The Heavy-Duty version offers a static load-carrying capacity of up to 1000 kg. Both cabinet frame types are designed for a 19" internal configuration. Since the floor footprint is the same for both frames, they can be combined in rows. All cladding elements such as doors, side and rear panels, covers and base plates can be combined with both frame versions. Heavy-duty accessories such as extra-robust shelves, slide rails etc. are available where particularly heavy assemblies are to be accommodated. A suitable cabinet is built up from these parts to suit specific requirements. NewTelco has opted for higher quality equipment and uses exclusively the Heavy-Duty version of the Varistar cabinet platform in its colocation centres.

These cabinets thus fulfil the functions required by NewTelco and the applications. However, NewTelco has been impressed not only with the cabinet design but also Schroff's flexibility, the quality of its products and its short response and delivery times, which suit the company's own philosophy.

Cold aisle containment with standard elements

When it came to creating cold aisle containment, the company turned again to Schroff for know-how and a joint solution, which New Telco now offers to house the equipment of its customers. The space intended for containment at the Rebstöckerstrasse 25-31/Kleyerstrasse 90 site now already contains a separate cage with a row of cabinets for one customer, already up and running. The room has a false floor and air conditioning, so a cold-aisle version of containment has been chosen.

As the basis for individual cold aisle containment units, basic elements from the Varistar cabinet programme have been chosen and adapted as required. The 45°-angled surface of the VARISTAR frame with its typical meander-style grid holes in the profile offers many universal fixing options. The powder-painted frames in steel with protective safety glass link the opposing rows of cabinets and close the aisle from above. If larger gaps, which must also be completely closed, are present in the cabinet rows, dummy elements are integrated that can be closed with e.g. a continuous front door.

These dummy elements can later be removed and replaced by real cabinets if further expansions are carried out subsequently. If the cold or hot aisle containment is sealed overhead, doors can be added to each end of the aisle to seal it completely. These doors may be wing doors or sliding doors, electrical or manually operated, with or without locking, with or without a motion detector, etc. Schroff containment elements are simple to fit or retrofit to the various different types of cabinet.

Two cold aisle containment units were built, with 24 cabinets each, and a third is in planning. The individual cabinets are fitted with locks and numerical codes so that only authorised personnel have access to the customers' equipment. Additionally, both cold aisles and the entire colocation floorspace are video monitored.

Of particular importance for the efficiency of the cold aisle is that it is reliably sealed. One of the components for this were special sealing elements that were developed in collaboration with NewTelco, and which Schroff now offers as standard components of its accessories programme.

The doors chosen are automatically-closing sliding doors: it is important to ensure that the aisle is kept tightly closed even when a technician is working within. Lights have also been installed in both aisles, that come on automatically when the doors are opened and that go out again after a preset time. These offer technicians sufficient light to do their work effectively. For cabling into the cabinets, various cut-outs and cable channels, as specified by the end customer, are integrated into the side panels so that customers using several racks side by side can make use of the internal cabling options. Cables can of course also be passed through the false floor or via cable panels over the cabinets.

Thanks to the flexibility of the Varistar cabinets, all options here can be realised. The two cold aisle containments were constructed by Schroff technicians throughout and took about two days per aisle.

The question of the expected energy savings obtained from the new cold aisle containment was answered by Moussa Remmo, director of network solutions and project management at NewTelco: "We estimate that we can save some 10 to 20% of our air-conditioning costs", he said in conclusion.