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Acoustic properties throughout the buildings are very good, with the incorporation of sealed, rigid construction, acoustic absorption in cavities (matting and/or heavy infill materials) and acoustic separation with the use of insulating layers and barriers.The heating system of the building as a whole was considered, with both the building envelope and heat sources considered together. The walls meet the new energy efficiency standards soon to be introduced as part of Ireland’s greenhouse gas reduction strategy, achieving a U-value of 0.23 W/m²K. This attention to energy conservation was integral to the building’s design, with the roof achieving a U-value of 0.16W/m²K, and the floor achieving a U-value of 0.25 W/m²K. The timber-aluminium windows used have argon filled double glazing with low emissivity glass, and typically achieve a U-value of 1.4W/m²K, depending on size.
Coillte is especially conscious of its commitments under the Kyoto Protocol to reduce CO2 emissions and believes that Ireland has a strong but as yet undeveloped potential for biomass energy production. With the large proportion of Irish forests that Coillte manage, they are in an excellent position to utilize this potential and start an Irish timber biomass industry through the harvesting of wood residue from saw mills and forestry (Editor’s note- there are already companies set to begin production of pellets from saw mills and forestry early this year).
In light of this, it makes sense that the new building contains a large-scale commercial installation of a wood pellet/wood chip fuelled boiler, used as the second stage heat generator for the building. The boiler installed was a KWB USV 100, which has an output capacity of 95kW and has an efficiency of 85.6% at rated output and 85.4% on part load. Coillte are hoping to demonstrate the wood chip capabilities but will be mainly running from a 20m2 adjacent pellet store via an automatic feed system including an agitator within the store and an automatic feed conveyor system. The boiler will deliver approximately 152000kWhrs of renewable heat a year, reducing CO2 by 27,360kg compared with natural gas.Two arrays of solar thermal panels, which are made up of a flat plate array and an evacuated heat tube array, are the primary heat source. A large buffer vessel is used to store this heat, which is topped up from the wood chip boiler when necessary. Both of these systems are located in a purpose built Energy Centre, which also contains full monitoring and feedback facilities. The Energy Centre generates heat entirely from renewable sources and is carbon neutral in terms of CO2 emissions. The building is fully sustainable with the primary building material being timber from sustainable sources, insulation by recycled paper product to levels better than current building regulations, passive solar design incorporating brise soleil, external fixed and retractable solar shading and very high quality glazing.
The building is open to the public for education and demonstration purposes and a meeting room has also been designed with full audiovisual facilities for lectures and discussion purposes.
Gerry Cunnane of Wind, Water, Solar Energy Systems describes the Thermomax Solar installation at the Coillte offices.
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The solar installation in the Energy Centre at the Coillte Headquarters consists of two separate Thermomax solar panels, one evacuated tube type and one flat plate, linked in parallel to a 1,500lt insulated buffer tank. Both solar collectors have the same effective area (9 square meters) and are fitted with data loggers capable of recording the respective outputs over time. In this way it will be possible to compare the performance of each collector type in Irish conditions. This information will add to the body of knowledge being built up regarding the performance of solar thermal in Ireland."
