With growing customer demand, the client urgently needed to add new technical space to their existing, overcrowded data centre. Timescales for growth were very tight to support business-critical growth in 2018.

With the existing technical spaces on the site being unable to accommodate the requirement it was decided that part of the PMC room located beneath the first-floor offices would be converted into a new technical space dedicated for the planned growth. This would also include the conversion of three existing small meeting rooms, an incident team room, kitchen and break out area.

At the very early design stages of this project it was agreed with the client to utilise the indirect free cooling benefits on offer by installing a chilled water system. With it being a brand-new technical space, it was the perfect opportunity to install this and maximise the potential energy savings.

Paul Drury

The project had high expectations due to the nature of the work and had many challenges including working within staff occupied areas. The team worked closely with our client and their consultants, maintaining a good working relationship to deliver a first-class project on budget and to programme, and continued the high standards we pride ourselves on maintaining and therefore we are especially grateful to our site teams and our sub-contractors for their professionalism and hard work.

Paul Drury, Project Manager



Long range plan growth project


International Television and Telecommunications Company


Berkshire, South East England


26 Weeks

The proposed room conversion was limited by the maximum room height.

Due to this factor, a suspended ceiling could not be installed, and only a small floor void could be installed for services only as opposed to it being a supply air plenum. In turn, this restricted the cooling solution as perimeter and external cooling options were unviable due to the restrictions of supplying the cold air to the racks and returning the hot air back to the cooling units. This meant the only correct solution would be to utilise InRow air conditioning units served by chilled water. The chilled water pipework would be installed below the raised floor and fitted with water detection.

The proposed room configuration and cooling scheme would provide full cold/hot aisle containment which would enable high free cooling opportunities. The proposed chilled water systems incorporated chillers with ‘free-cooling’ economisers to take full advantage of this opportunity. The scheme could utilise two independent chilled water systems to minimise the chance of cooling system total failure.

The InRak air handling units are able to provide N+1 cooling to each contained cell and each unit would have integral variable speed pumps which could vary the chilled water flow to provide the necessary cooling to match the load. This variable flow rate scheme negates the requirement for modulating control valves and limits the power absorbed by water pumps to an absolute minimum. The chillers would be selected with generously sized heat exchangers and adiabatic spray cooling to optimise the plant efficiency and overall PUE.

Mid project constraint and the solution

Due to the massive time constraint set by the client, it was agreed to proceed at risk before we had received landlord and planning approvals for the external plant that would have been located in the car park. This meant that whilst we were waiting for these approvals, the new technical space was created, and the chilled water pipework was installed under the new raised modular floor.

As part of the creation of the new room, a new Novec 1230 gas suppression system and extract were installed. Fibre, data and power containment were also installed, and SCADA fault and energy monitoring were added to the room. Once this was all in place, we then received the information that there were issues with the planning application submitted for the use of the external car parking spaces for the outdoor chillers.

A new solution was quickly sought so as not to delay the programme. As a quick fix, to ensure the client could install their growth requirements by their deadline, a temporary DX InRow AHU system was installed instead of the chilled water system originally proposed.

Due to the DX system being installed, free cooling is not possible. Eight DX InRow AHUs were installed in the contained cell that was created and the outdoor units for these were installed under an existing gantry. This set the room up ready for growth to be installed.

The chilled water pipework that was installed under the raised floor was left in situ as the client expects to eventually receive the landlord and planning approvals for the original scheme. When this occurs, the DX InRow AHUs that were installed would be swapped out for new chilled water InRow AHUs and the external chillers could be installed as per the original design to ensure the new technical space gains the benefits from the free cooling potential.

With the chilled water pipework system designed and installed to the original scheme, there is now the possibility to expand the room further in future, creating an additional fifteen growth spaces beyond the original growth requirement for this project.