Company Announcement - At R3bn, St Helena Airport development represents one of the largest construction projects awarded to a South African construction group by the UK Department of International Development. Basil Read, the successful bidder, has estimated the ST Helena Airport build time to be four years with the completion date set for early 2016. The airport project, when completed, will measure 3500m2 and offer landing facilities for aircrafts up to an Airbus A320 or Boeing 737-800. The airport building is designed as a mixed-use development which includes the terminal building for arrivals and departures and (limited) office and retail space.

Mixed-use buildings are generally the most challenging buildings to keep comfortable. With the wide variety of environments, the cooling and heating needs of the ST Helena Airport are significant. HVAC specialists, Worley Parsons Engineering were appointed to assist on the project, with 52 Engineering acting as the onsite HVAC contractors.

Due to the geographical location the island has restricted access and a trip to the island could take up to 3 weeks (round trip). 52 Engineering chose Mitsubishi’s ‘CITY MULTI’ as the successful HVAC unit for the project. The CITY MULTI provides the client with powerful and efficient - yet flexible - solutions that help the engineers meet a wide range of requirements, whilst reducing installation time and project costs.

Choosing the Mitsubishi Citi Multi
There is over 25 years of history between the two companies; back-up service was another major factor why 52 Engineering chose the CITY MULTI. Mitsubishi is renowned for their back-up service and spares availability. The Citi Multi offers a CITI MULTI controls network or CMCN. The CMCN manages up to 2,000 indoor units from a single networked PC.
The CMCN sets and monitors operation, mode, temperature, fan speed and airflow direction and even includes an operating schedule that's tailored to the needs of the people and the building. The network manages operation, monitoring, scheduling (daily, weekly, yearly) error email, personal browser, and tenant billing and maintenance diagnostics.

CITY MULTI performance versus cost
The City Multi can heat and cool using minimal energy and has a high coefficient of performance. The world’s only two pipe simultaneous system means that by eliminating the 3rd pipe, the CITY MULTI costs less, is quicker to install and is more reliable. The amount of piping sites is also reduced. The Key to the CITY MULTI system lies in the BC controller. The controller houses a liquid and gas separator allowing the outdoor unit to; deliver a mixture of hot gas for heating and cool liquid for cooling, out of the same pipe. The more the heating and cooling process is engaged the better the COP performance. The unit also has the ability to regulate temperature through the “changeover mode”. This allows for maximum comfort throughout the multipurpose structure. The ST Helena Airport building will be installed with a mixture of
midwall, cassette’s and hideaway units. The fresh air volumes (L/s) will range from 30 to 60 volumes. Air supply will vary from 333 to 630 volumes.

The operations phase of the airport contract will continue in partnership with Lanseria Airport for a period of 10 years.