By 2026 as much as 15 per cent of all electricity demand here will come from data centres and, with this expected growth, the third level sector should consider developing a specialist mechanical and electrical services module for data centres and other energy intensive buildings, writes Brendan Dervan.

Most mechanical and electrical (M&E) consulting engineers in Ireland will agree that one of the biggest challenges to growing their business is finding suitably qualified engineering staff.

Also if they are asked as to what sector of the industry they would like to get more involved in, most will mention data centres, pharmaceutical, medical devices or similar high-tech sectors.

For building services engineers and contractors these sectors are considered to be quite specialised and lucrative compared to other sectors such as residential, retail, commercial and education.

The clients in these high-tech sectors tend to be very well informed, knowing exactly what they want in terms of engineering services, reliability, adaptability, scalability and so on.

The M&E services in these projects are considerably more complex than those found in the aforementioned sectors. This article specifically focuses on the challenges in the data centre sector which the author has been involved with over the past 15 years.

Growth in demand for data centres

The main driving forces behind the demand for new data centres (DCs) is the continued growth of cloud computing, social media, online retail, video streaming and the like.

In its recent ‘All-Island Generation Capacity Statement’, which includes forecasts to 2026, EirGrid states that there are currently about 250 MVA of installed data centres in Ireland, with another 600 MVA of capacity applications being processed at the moment.

It notes that there were inquiries for more than 1,000 MVA for future data centres. Their forecast for 2026 is that DC demand could be as high as 1,400 MVA as indicated in Figure 1 below.

Figure 1: Anticipated growth in data centre demand 2016-26 - EirGrid

According to its mid-range scenario, by 2026 as much as 15 per cent of all electricity demand in Ireland will come from data centres.

In addition to this demand for new DCs there is an on-going need for modernising of earlier generation DCs typically built in the early 2000s.

Types of data centres

At this point it is worthwhile describing the function of a DC and the specialist M&E services required to facilitate their operation.

A DC is a facility used to house data processing equipment such as servers and networking and storage systems. This equipment is commonly referred to as information and communications technology (ICT) equipment or sometimes just information technology (IT) equipment.

The ICT equipment is housed in racks which are essentially cabinets, typically measuring 600mm wide x 1,000mm deep x 2,000mm high. Racks are bayed together in rows with intervening hot and cold aisles.

DCs can be described using four main categories namely: hyperscale, colocation, private and edge.

Hyperscale DCs are typically built by large-scale ICT companies or the huge internet organisations, such as Amazon, Apple, Facebook, Google, and Microsoft. They generally build and operate their facilities to manage hosting for their own clients.

Colocation DCs are typically those funded and built by private investors for a single large client or multiple smaller clients. They are commonly referred to as 'colos'.

Examples include: Digital Realty, Equinix, InterXion, K2, EdgeConnex and Keppel. In these colos, customers can rent space for ICT equipment and are provided with the storage and networking equipment to connect them to a variety of telecommunications services providers.

They are also provided with power, cooling and the physical security for their ICT equipment. For most companies colocation is more cost effective in terms of capital and operational expenditure. It is a more energy efficient and more secure solution overall.

Private/enterprise DCs are facilities purposely built by financial, telecom and public services sector bodies for their own use. Examples include: BT, Eir and government agencies.

To meet requirement for higher bandwidth, reliability and scalability, many small or medium private DC operators have moved to cloud service providers (CSPs) and/or have outsourced to colocation facilities.

CSPs are basically companies that offer network services, infrastructure, or business applications in the cloud.

Edge data centres, which are typically located on site or at locations near to end-users, are becoming more common. They are required to complement existing cloud or colocation facilities and reduce latency.

M&E systems in DCs

The design of the electrical power system in a DC is complex and requires specialist knowledge not normally required on other building services projects.

On many of the hyperscale DC projects the grid connection is at 110 kV. The primary distribution around the site is usually at 20 kV or 10 kV depending on the size of the campus.

The scale of power system in a DC is often more akin to an electrical utility network typically distributing tens of megawatts. Compare this to a typical building services project with average demands in the order of hundreds of kilowatts.

Downstream of this primary MV distribution system is the main LV system, which supplies the data processing equipment and the cooling systems.

The requirements for current maintainability and fault-tolerant systems means that a considerable amount of redundancy has to be designed into the MV and LV network including transformers, generators, UPS systems right down to the rack power distribution units (rPDUs) serving the data processing equipment.

ICT equipment generates considerable amounts of waste heat ranging from two to 20kW per rack and more in very high density applications. Traditionally cooling has been provided by means of computer room air conditioning (CRAC) units located around the perimeter of the data hall.

These CRACs discharge cooled air into a raised access floor plenum which, in turn, delivers it to the racks via perforated floor tiles located in a shared 'cold aisle'.

The cool air is typically drawn in into the front of the racks and rejected out through the rear into a shared 'hot aisle' and from there it is returned back to the CRAC unit for recooling.

Evaporative or adiabatic cooling systems

Evaporative or adiabatic cooling systems are the most popular choice for most new DCs. These systems use the latent heat of evaporation to reduce air temperatures.

To avoid the obvious hazard of excessive humidity the approach is generally to use air to air heat exchangers with the evaporative cooling facility reducing the temperature of the primary (non-DC) air.

In some conditions, evaporative coolers can use as little as a quarter of the electrical energy that an equivalent vapour compression type refrigerant system uses.

Again the scale and capacity of the cooling system and the requirement for redundancy means they are more complex than cooling systems used in non-critical buildings.

The design of fire detection and alarm systems in DCs is also quite complex, particularly the systems in the data halls which have high velocity air streams.

The cause and effect control strategies, in particular the interfaces with cooling and fire suppression systems in the data halls and power rooms, requires special consideration.

Data centres by their nature need to have high levels of physical and electronic security. Physical security typically comprises fences and barriers around the site to prevent unauthorised access.

The electronic security systems, which normally form part of the other M&E engineer’s package, include perimeter intruder detection systems with video surveillance systems and access control throughout the entire DC.

In addition to the normal requirement for a building management system (BMS), data centres usually have a separate electrical power management system (EPMS) and a data centre infrastructure management system (DCIM).

The design and specification of these systems usually forms part of the M&E engineer’s package. The functionality and complexity of these is beyond what would be encountered on a normal building services project.

Academic courses for data centre design engineers

So how will the M&E sector in Ireland resource this expected growth in the DC sector? In terms of M&E contractors, the sector in Ireland is dominated by the likes of Mercury, Jones, Winthrop and Dornan and a few other large M&E contractors.

Most of these contractors also have experience working in the key DC locations in Europe including London, Frankfurt, Amsterdam, Paris and Sweden. Ireland’s good reputation in this sector is well established.

Similarly most of the larger-scale DCs in Ireland have been designed by a number of M&E consultants specialising in this area including Cundall, Arup, Ethos and O’Callaghan’s. As previously noted, they and other consultants are all struggling to get suitably qualified engineers to design these and similar complex projects.

Limited number of courses

There are a limited number of DC related courses available in Ireland. Sligo IT offers a BEng in Data Centre Facilities Engineering. This is a two-year - NFQ Level 7 programme.

TU Dublin/IT Blancharsdown offers a Certificate in Data Centre Operations (one year - NFQ Level 6) and a Bachelor of Science (two years - NFQ Level 7 in Data Centre Operations and Management.

These programmes were developed in partnership with industry providers including Google, Facebook and Microsoft in order to meet the growing need for specialist service and facilities personnel.

There are also some industry-led courses which mainly focus on the ICT aspects of the DC. However, there is very little out there in terms of design of M&E systems for these complex buildings.

Data centres are highly energy-intensive buildings with typical consumptions in the order of 30,000 kWh/m2 per annum. This is considerable when compared with 200-300 kWh/m2 per annum for typical non-air-conditioned offices and public buildings.

As previously noted, EirGrid predicts that by 2026 as much as 15 per cent of all electricity demand in Ireland will come from data centres.

With this expected growth of the sector, I believe it is time for the third level institutions to consider developing a specialist M&E services module for data centres and other energy intensive buildings, perhaps as part of one of the existing Level 8 or 9 courses.

Author: Brendan Dervan is a chartered engineer with more than 40 years’ experience in building services. Since starting his own firm, Dervan Engineering Consultants (DEC) in 1999, he has been involved in the design and project management of M&E services for existing and new DC facilities. He retired from mainstream consultancy in 2019 and set up Best Training which provides specialist CPD services to the M&E sector.