The Engineers Ireland Thomond Region held a site visit to the Lahinch leisure centre in late September to share knowledge of the deep retrofit project that was completed by the Tipperary Energy Agency.
The fact that the leisure centre was bustling with activity and the facilities were in high demand during the visit is a clear testament to the project's success.
Lisa Vaughan, CEO of the Tipperary Energy Agency, said: “The Tipperary Energy Agency was delighted to host the Engineers Ireland Thomond Region at the Lahinch leisure centre and to share our experience and learning from the project with the group.”
Transformed into a near zero energy building
The deep retrofit has transformed the centre from an inefficient and poorly insulated building to a near zero energy building (NZEB). Before the project began, an initial building survey by the project team assessed that the facility had a building energy rating (BER) of E.
Following a two-year retrofit project, the leisure centre is now an A-rated building with nearly zero energy building (NZEB) status which provides significant savings in running costs and energy efficiency.
John Hayes and John Hassett, from the Tipperary Energy Agency, gave a guided tour of the deep retrofit. The well-attended event reflected the widespread interest in the Lahinch leisure centre retrofit. The success of this project is a source of inspiration for future sustainable and energy-efficient building transformations in the country.
David Purcell, chair of the engineers Ireland Thomond Region, said: “It is not often we get the opportunity to see several renewable engineering technologies combined in one facility. This visit to the Lahinch leisure centre shows that we can reduce our dependence on fossil fuels and contribute to a more sustainable and cleaner energy future.”
Quality, sustainable, agile and diverse multiservice social enterprise
The objective of the regeneration project was to deliver a quality, sustainable, agile and diverse multiservice social enterprise and key infrastructure hub in a high-profile strategic location. The project design focused on the energy conservation and systems to efficiently manage the specific standards of a leisure centre.
The deep retrofit design included some very unique solutions to the challenges this project presented. Due to the lack of space, the geothermal heat pump system design was delivered by boring fifteen 150-metre boreholes to give a total borehole length of 2,250 metres outside the building.
The system is operated using two 79Kw ground source pumps which serve two direct hot water cylinders, one 700-litre pre-heat tank and a 700-litre finish tank.
With more than a year in service the geothermal system is performing better that expected as the ground temperature is being maintained at a constant temperature due to the tidal movement from the sea. An average measure coefficient of performance (COP) of 3.7 was delivered.
On the day of the visit the sun was shining and the SolorCo display for the photovoltaic (PV) Solar system showed that it was delivering 79 KW of the 80KW that the facility was using for its operation. Therefore on this day in September the Solar panels were almost providing all the energy the facility required to run which considering it has a heated swimming pool is impressive.
The installed PV system has 310 solar panels (445w per panel) with two Solis 40K-5G inverters and one Solis 50K inverter. At times when the energy demand is lower, any excess electricity generated can be stored in the 30KWh battery storage system included that comprises of nine pylontech US3000 batteries.
The benefit of the new smart LED lighting in the leisure centre includes occupancy detection and daylight sensing. The 416 LED lights automatically adjust their intensity based on the demand.
Daylight sensors save energy by dimming or turning off electric lighting when sufficient daylight is available and the occupancy detection switches the lights on or off depending on room usage.
Geothermal heat pump system
A wood pellet biomass boiler was installed to provide back up to the geothermal heat pump system and consists of one 300KW boiler, a 100W boiler and a 10,000-litre buffer tank.
The biomass system is used to assist the domestic hot water production in times of high usage or heat pump downtime. The total estimated thermal consumption is 483,000 KWh.
Some of the lessons learnt from the installation that should be considered for future projects were
The AHU retrofit could have included larger heating coils for future heat pump demand for low pressure hot water (LPHW).
The solar PV size could have been greater. There is a substantial night-time load on the facility and a higher capacity PV array would have utilised the battery storage more.
The original plan for the biomass boiler was to install two 300KW boilers but due to budget constraints, value engineering resulted in a 100Kw boiler installed with a 300KW boiler. If the 300KW boiler is offline the smaller boiler struggles to maintain temperature.
Following the retrofit, Lahinch leisure centre is now a best-in-class A rated leisure centre with up to 55% reductions in running costs and CO2 emissions.