EDC Engineers & Contractors

What We Do

Our expertise include many services that are applied to a number of applications as is discussed in the "Expertise and Services" tab of this website. They are applied to environments such as chemical plants, high rise buildings and industrial factories, but our main focus remains with intricate installations in the Data & Communications field. A general overview of what a Data Centre comprises of is set out in short below:

Data centres are secure facilities used to house data processing, communication services and storage devices that in most cases are extremely valuable. Operational losses of these services are to be limited to the utmost extremes. Depending on the importance of the data information, the complexion of a specific data centre design will be allocated and as such be classified accordingly. The classification directly influences the installation cost and must therefore be carefully weighed up to the risk of losing any data as well as the resultant cost implications.

Once this has been determined, an appropriate data centre classification can be made.

Data centre classifications, in accordance to the Uptime Institute, are categorized into four groups; namely: Tier I,

Data centres

Tier II, Tier III and Tier IV. These tier ratings consist of various requirements of which the paths of availability to the loads must be highlighted as they will ensure continuous operation of the facility.

The following basic criteria must be adhered to in order for a facility to be liable for such a specific Tier classification.


Tier I: Basic: 99.671% Availability
  • A data centre of this nature offers one path of power and cooling only and has no redundant components on offer.
  • Generally this should be the cheapest installation of the four types of Tiers.
  • As a result it will be susceptible to disruptions of both planned and unplanned actions and experience complete shutdown when preventative maintenance is being performed.


Tier II: Redundant components: 99.741% Availability
  • This category is less susceptible to disruptions that Tier I installations for both planned and unplanned actions.
  • It has a single path for power and cooling is but includes redundant components (N+1)
  • Maintenance of all paths requires a processing shutdown.


Tier III: Concurrent Maintainable: 99.982% Availability
  • In simple terms; no disruptions will occur for planned actions but for unplanned actions disruptions may occur.
  • It has multiple power and distribution paths but only one is active at a time. It is also a N+1.
  • It allows for sufficient capacity via each path to the load such that maintenance can be performed without disruptions.


Tier IV: Fault Tolerant: 99.995% Availability
  • Planned actions will not disrupt the supply to the critical load. Also, at least one unplanned worst-case fault is permitted at a time without any impact on the critical load.
  • A multiple number of power and cooling paths is supplied to the critical load equal to two times (N+1).

The electronic equipment used in these environments have an ideal operating ambience in terms of temperature and relative humidity levels. Should they operate outside of these parameters their life expectancy may be shortened and eventually lead to component failure.

It is therefore important for the data centre’s environment to be effectively regulated and continually kept within these specific parameters. Generally the areas housing the electronic equipment are regulated by means of computer room air conditioners (CRAC) which ensure that the parameters are met. They are as follows:

Temperature must be between 16 and 24 degrees Celsius at a relative humidity of between 40 and 55% at a maximum dew point of 15 degree Celsius.

Other than the very important power and cooling paths many other factors are also taken into consideration when grading a data centre in accordance with the Uptime Institute. The following factors must be taken into account but are not limited to:

Telecommunication paths, site location, parking, building construction, building components, computer room ceiling, roofing, doors & windows, entry lobby, administrative offices, security offices, operations centre, UPS and battery rooms, exit corridors, generator and generator fuel storage room, security, security access control & monitoring, bullet resistant windows, door & walls, CCTV monitoring, structural, UPS supplies, grounding methods, emergency power, load bank tests, water cooled systems, chilled water cooled systems, air cooled systems, fire detection & alarms and fire suppression systems.

Here is a very basic layout of a data centre using the raised floor concept. The coloured lines show the cooling method used and typically how the data and power services are installed. There are however many different possibilities in the design applications and the layout below simply features as an example.








What We Do




What We Do