A client of FEL Group had an urgent requirement to facilitate significant additional customer growth. A local MP announced that the Governments desire was that “everyone in the UK to benefit from world-class connectivity no matter where they live, work or travel” this pledge was also given a very challenging short deadline and FEL Group were tasked to meet this demand with little flexibility on timescales.

The concept of prefabricated modular and portable buildings is growing in popularity. Modular data centres can be designed and constructed to detailed specifications in a controlled factory environment.

Pre-commissioned, they considerably reduce time on site normally spent validating the operation of services from cooling through to Monitoring software.

Modular data centres offer scalable growth of IT infrastructure and the flexibility to modify the design and size of future plans of development.

Modular buildings arrive on site ready to deploy, which in turn significantly reduce on site installation/programme costs.

Modular data centres by nature are relatively small, an optimised footprint is essential, leading to function specific modules that can accommodate larger capacity racks and providing a greater kW per square metre ratio.

This site is a new containerisation switch room, purposely built for the requirements for new housing growth within the Margate area, FEL provided the design concept which the customer was delighted that the concept will back up the existing provision on site. From start to completion FEL Group and their associates have been professional in their work on and off site, and always maintained close contact with the local businesses ensuring that the construction works did not impede in any way on their business or customers. Safety is a key topic within the company and we have had no issues at all while FEL have carried out their installation and delivery works

Mark Thompson, Technical Site Inspector South East Region



New Modular Solution


International television & telecommunications company


Thanet, Kent


20 weeks

Modular Build Room PUE


The existing site is a fully populated hub, that had no further room for any future IT server rack cabinets, a new build solution was the only option.

Logistically, there was a short driveway up to the site with a small car park. An external generator, fuel tank and unused greenfield land owned by the client next to the existing site and car park. Filled with shrubbery and hedges this land backed onto a security fence which enclosed the whole site.

Outline planning permissions and landlord approvals were obtained to use this land as a potential solution using a new modular building concept to house the proposed customer growth. Once approved, a noise survey and a utility detection and mapping ground survey were carried out.

The next new challenge became evident when the site was highlighted as being located within a Zetica high-risk bomb area with bomb strikes recorded close to the site.

This risk clearly needed to be mitigated immediately to comply with CDM regulations. An initial desk study was carried out which included a preliminary UXO (Unexploded Ordnance) risk assessment which enables the surveyors to quantify the risk further.

An additional detailed survey of the UXO area was undertaken with a suspicious object identified. Recommended procedures were undertaken in order to remove the object and make the ground safe and viable for the proposed works to continue.

The land was cleared, and a new trench was excavated to join with the existing DNO services route. A new paved footway and concrete slab were installed ready for the installation of the new modular data centre building.

The modular data centre installed features a wall structure that incorporated a mild steel, primed, structural framework to take the wind and lifting loads. The external wall skins were formed from zinc coated steel sheets with vertical and horizontal stiffening members to cater for the wind loading. A proprietary, modular raised flooring system was installed comprising of base-plate support adjustable pedestals complete with cruciform head and nominal 600mm x 600mm x 42mm access flooring tiles finished in antistatic vinyl. The building was manufactured as to ensure effective retention of the fire suppression gas. The building also has a rating of IP54 with doors rated to IP4X.

The options for optimum energy efficient cooling were explored.

Direct “Free” cooling was proposed; however, this site is situated in a coastal location, whereby directly supplied fresh air would bring saline saturated air into the technical space leading to increased levels of corrosion.

Various water chiller options were assessed but were soon rejected, as it was highlighted there was no permanent water supply on site, plus energy calculations showed longer ROI’s.

The cooling option selected that met the best energy profile, with all the site constraints considered became DX InRows.

Two Airedale LIR6042U-X240-0 InRow AHUs were installed in a new contained hot aisle within the modular building, with the option to add a third as the IT load is increased above the current requirement. The Airedale InRow AHUs featured EC fan motors, N+1 fan redundancy, refrigerant leak detection and microprocessor controls with graphical display.

The AHUs were to control the supply air temperature at 21°C. The associated outdoor condenser units for the AHUs were located at the rear of the building within a dedicated security cage, whilst still allowing space to permit future growth.

An additional benefit for our customer for this particular modular solution, is that there is a potential requirement to move this entire IT growth to another more suitable site in the future. This modular solution would therefore enable a faster timescale for this undertaking.

Other works:

  • Electrical services included new fibre guide, RF basket, DC and AC containment, a new 10kVA Liebert NXC UPS system and Batteries.
  • New UPS distribution boards, and a new UPS external bypass switch were also installed.
  • A new Novec 123 system and extract were installed along with a 600mm raised floor for services such as power and pipework.
  • A new Enrogen EG180PQ generator was installed, powered by a new Perkins 1106A70TAG3 diesel engine coupled to a Leroy alternator with a prime output of 180kVA along with reinforced concrete raft.
  • A new LV Switch panel complete with generator ATS and Comap controls. Cabling was also installed from the LV switchboard to new DC input distribution boards and additional DC rectifier units.
  • Independent steps with level landing and handrails were installed for access to the building with a weather canopy above.
  • The existing security fencing was replaced with a new galvanised steel 2.4m high security fence.
  • Also, a retaining wall was installed around the new modular building.
  • Red and blue LED lighting was installed to indicated hot and cold aisles within the modular building.
  • Existing electrical fibre trench was used to link between the existing site and the new modular building.
  • Full TMAC and SCADA monitoring system.