Lansdowne Gate Development

Origen Energy Ltd, in conjunction with Patrick Dunphy Consulting Engineers and Cosgrave Developments, undertook the design, supply and installation of a district heating system at the Drimnagh Castle site between the Naas Road and Longmile Road in Dublin 12.

The brief entailed the construction of a centralised boiler-house providing 2500kW of low pressure hot water to a site consisting of 280 apartments spread over 7 blocks, whilst minimising the space consumed by the boiler-house itself.

It was agreed between Origen and Patrick Dunphy Consulting Engineers, that the Wessex Modumax 250c range of boilers be utilised, as they offered minimal plant size, coupled with higher than normal efficiencies (91% seasonal) along with a modulation turndown rate unrivalled by any other boiler (minimum 50kW output). Coupled to this, the boilers were supplied complete with the specialist water manifold kits that facilitate complete reverse return through the boiler banks and reduced the installation time by 80%.

District heating works like a domestic central heating system, only on a larger scale. Water is heated by the Hamworthy Central Energy Centre and will be circulated through a pipe network to each dwelling in Lansdowne Gate. Each dwelling has its own separate meter and an electronic system to control the internal temperature.

As with all district heating systems Origen have been involved in, we were able to offer technical assistance with the sizing of the pumps, the distribution pipework selection, flue installation, system expansion tanks and also the controls associated with the whole installation.

Special attention had to be taken when designing the pipework and pipework runs within the basement, as the pipes would be carrying hot water 24 hours a day, seven days per week. Attention was drawn to the supports and bracketing arrangements used, as they would act as thermal bridges to the structure of the site and reduce the efficiency of the system.

In the end, the boiler-house ended up occupying only 3 car parking spaces, spaces that can cost up to €35,000 each in Dublin.

It was decided that the site be split into 2 circuits as it was calculated that the size of the distribution system would be detrimental to the temperatures of the water in the system.

Once inside the apartment, Origen supplied district heating sub-stations, that produce instantaneous hot water for the occupier along with continuous and accurate meter reading of all water services entering the apartment. This facilitates accurate billing to each occupier.

The site has proved to be a landmark site for Cosgrave Developments, as visits have been made to the site by Sustainable Energy Ireland (SEI) and also the Minister for the Environment, as a demonstration as to how Ireland can make serious inroads towards reducing carbon emissions.