Kerrigan Mechanical excelled in delivering an exceptionally energy-efficient and sustainable mechanical services installation for the Premier Inn Gloucester Street South Dublin project, resulting in it attaining a BER A2 rating – the highest possible rating achievable.
The scope of works encompassed the installation of plumbing, heating, soils, ventilation and air conditioning systems to the 11-storey, 113-bedroom, city centre hotel.
The project presented several challenges. The hotel had a small footprint and was located in close proximity to schools, making logistics and site access challenging. Furthermore, the restricted height of the floors posed coordination difficulties, particularly in view of the extensive pipework required on each floor. As a result, the project necessitated meticulous coordination to accommodate all mechanical and electrical services within the allocated spaces.
The impressive BER rating of A2 highlights the exceptional energy efficiency and environmentally friendly design of the mechanical services. This accomplishment was made possible by implementing a combination of heat pumps and gas boilers for the hot water system, as well as utilising Hybrid VRF air conditioning. The installation of Hybrid VRF air conditioning played a vital role in achieving the higher energy rating. Unlike standard VRF systems that rely solely on refrigeration, Hybrid VRF incorporates a blend of refrigeration and water. This approach significantly reduced the need for refrigerant gas and associated leak detection systems.
Kerrigan Mechanical installed four heat pumps in a cascade arrangement on the roof, which were supplied by Mitsubishi Electric Ireland. Mitsubishi also provided hybrid VRF Air Conditioning which provided heating and cooling functionality through an interface in each room. Each room was equipped with a bespoke Premier Inn logo and featured local temperature control, which could also be adjusted via the Building Management System (BMS).
The hot water system throughout the building, including showers, toilets, kitchen and other facilities, relied on the heat pumps being capable of reaching temperatures up to 55oC. At any given time, the hotel has 4,000 litres of hot water on standby at 50oC to 55oC, stored in two stainless steel tanks. The final temperature increase of 10oC to 60-65oC (to prevent Legionella growth) was achieved using a gas-fired water heater, significantly reducing gas consumption and extending the longevity of the boilers. Additionally, this approach minimised CO2 emissions, playing a crucial role in attaining the A2 rating.
To overcome challenges posed by the hotel’s close proximity to the River Liffey and the high water table, a bespoke sump pump designed by GlennGorey Pumps was installed in the basement to facilitate effective water extraction. This innovative solution demonstrated the firm’s commitment to problem-solving and contributed to the successful completion of the installation. Throughout the project, Kerrigan Mechanical also collaborated closely with SR Ventilation, Crystal Air, Ashdown Controls and FläktGroup, amongst others. These partnerships ensured seamless integration of ventilation systems, BMS, fire dampers, ductwork, air conditioning, electrical work, critical alarm systems and sump pump. FläktGroup provided the kitchen supply AHU, extract fan and life safety fan-assisted smoke shaft and worked alongside Kerrigan Mechanical in the commissioning phase to fine-tune the systems, ensuring complete compliance.
Commenting on the project, Adam Dent, Contract Manager for Kerrigan Mechanical said, “Delivering the Premier Inn Dublin project on time and within budget while achieving such an exceptional energy rating was a remarkable accomplishment for us. It serves as a testament to Kerrigan Mechanical’s ability to deliver high-quality results within strict constraints.
“I would like to thank our own team for working so diligently, as well as the input from our suppliers and partners in the project.
“We are a young and progressive business and we pride ourselves on constructing high performance and energy efficient mechanical solutions, which contribute towards Irelands drive to reach agreed emissions targets by 2030. We are proud to play our small part in this, to ensure that our environmental impact is minimised.”
Unit 3, Athboy Business Park, Trim Road, Athboy, Co. Meath
T: +353 (0)46 94 30529
www.kerriganmechanical.ie
For the full feature on Premier Inn Dublin, check out Ireland’s Plumbing & Heating Magazine Issue 114 July-August here.
