Bagenalstown – Carlow – Ireland
LPG boilers replaced by environmentally friendly, cost effective heat pumpsBackground
Bagenalstown Swimming Centre is managed by a voluntary management committee, the Bagenalstown Swimming Club. Every year the club sets a new goal to improve the facility in some way.
In 2004 this goal was to improve the thermal comfort of the pool in a cost effective and environmentally friendly manner. To this end, it was decided to replace the existing liquid petroleum gas (LPG) boilers with a 30kW output water to water heat pump to heat the pool water and a 1.8kW output air to water heat pump to heat the shower water.
Installation of the heat pumps has reduced the pool’s heating costs by over 50%, with an associated 60% reduction in annual CO2 emissions.
Bagenalstown Swimming Centre
Building details |
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| Type of building : |
Swimming centre including a 25m outdoor pool, a children’s paddling pool, fully equipped communal changing rooms and showers and disabled access changing rooms. |
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| Year of construction/ Floor area/ Operating hours : |
1947 / 25m pool / operating hours : 155 days (June to September), heat pump operational 11.00pm – 12.00 noon. |
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| Heating and cooling / measures installed |
One 30kW water to water heat pump system for heating the pool water and one 1.8kW air to water heat pump along with a 500 litre factory insulated hot water tank to heat water for the shower facilities. |
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| Energy/CO2/Water label (before and after improvements if possible) |
CO2 savings : 11 tonnes/year Energy savings : from 83MWh/year LPG to 12MWh/year electricity |
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ProjectDescription |
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| Aim |
The goal of this project was to improve the thermal comfort of the pool in a cost effective and environmentally friendly manner. |
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| Key points |
During a review of the facilities at the pool in spring 2004, the management committee decided to consider a number of alternative options to reduce the cost of heating the pool while increasing its temperature to make it more comfortable for its users. The decision to replace the existing LPG boilers with water to water and air to water heat pump systems was based on a number of factors :
- Heating with a heat pump system is more economical than using LPG ;
- Heat pump technology is reliable, convenient and environmentally friendly ;
- The River Barrow running adjacent to the swimming centre can provide a huge source of energy.
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_ The River Barrow runs adjacent to the swimming centre
_ Key drivers leading to the improvements
There were several drivers that led to implementing this renewable energy project. These included :
- Increasing the comfort of pool users.
- Reducing the centre’s running costs.
- Extending the opening season of the swimming centre.
- Utilising an environmentally friendly energy source.
In addition to this, the existing boilers were due for replacement within the next few years. These boilers were inefficient and the provision of maintenance and spare parts was proving difficult.
_ Water to water heat pump
A 30kW output water to water heat pump system was installed for heating the pool water. This system was manufactured by NEURA Electronics and installed by Eco Heat Limited. The heat pump replaced two 400,000 BTU LPG direct-fired boilers.
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_ Old LPG Boilers
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_ New 30kW output water to water heat pump
_ River water is pumped from an underground spring adjacent to the centre and passed through the heat pump’s heat exchanger. This lowers the temperature of the water by approximately 4°C in the process of extracting energy from it to heat the pool water. The cooled river water then flows back into the River Barrow downstream of the intake point. The efficient operation of the water to water heat pump requires the source water temperature be at or above 6°C during operation. During the pool’s opening season, the source water temperature remains at 12-14 °C, thus allowing the system to operate very efficiently. The temperature of the pool water needs to be increased by 12-13°C above ambient temperature, i.e. 24-25°C, to maintain comfortable pool conditions.
_ The coefficient of performance (CoP) of the system is calculated to be 5:1. In other words, for every 1kWh of electricity used by the heat pump, 5kWh of heat is delivered to the pool water. The source water passing through the system will lose 4°C of heat as it passes through the heat exchanger. For each °C temperature drop, 1.2kWh per cubic metre of water is obtained, or 4.8kWh per cubic meter under normal (4°C temperature drop) operating conditions. When operating at full capacity, the 30kW heat pump will require a throughput of 5.5-6.5 cubic metres of water per hour. The estimated energy production of the heat pump is : 6m3/h x 4.8kWh/m3 x 13h/day = 375kWh/day.
_ There is still one operational 130,000BTU LPG direct fired boiler used for heating the children’s paddling pool. This will have been replaced with a new heat pump by summer 2007.
_ Air to water heat pump
In addition to the water to water heat pump, the centre also installed a 1.8kW output (0.63kW input) air to water heat pump along with a 500 litre factory-insulated hot water tank to heat water for the shower facilities. This system was also manufactured by NEURA and installed by Eco Heat Ltd. The heat pump replaced one 80,000BTU LPG indirect-fired boiler. The basic specifications of the system are as follows :
- Flow temperature maximum of 55°C ;
- Optimum soundproofing using special fans and air deflection hoods and a special steel base frame ;
- Energy efficient, self-learning defrosting via circuit reversion and inclined evaporators ;
- Constant water flow temperature ; and
- Sheet metal casing with corrosion protection.
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_ New air to water heat pump and hot water tank
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| Reason for inclusion as Shining Example |
This Shining Example showcases the use of heat pumps that utilise renewable energy sources (latent heat in water and air). In this case the swimming centre has achieved over a 50% reduction in their annual heating costs and a 60% reduction in annual CO2 emissions, with a payback period of 4-5 years excluding grant assistance.
_ Closer examination of experiences in other swimming pools around Europe and of Irish case studies of different building types using heat pumps played an important role for this project by highlighting the benefits of heat pump technology and overcoming any perceived barriers from lack of knowledge. |
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Costs&Benefits |
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| Costs &
funding
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The total capital and installation cost was €22,000. The heat pumps have been set up to operate on night-rate electricity. This combined with the 5:1 efficiency of the heat pumps has resulted in a reduction in the centre’s heating costs of over 50% and has allowed for the option to economically extend the opening season of the pool by up to 3 months per year.
_ With €9,000 grant assistance provided by Carlow Leader Rural Development Company Limited, the installation will pay for itself in 2-3 years (or 4-5 years, including ‘paying back’ the grant assistance). The remainder of the funding was generated by Bagenalstown Swimming Club who ran a number of fund-raising projects.
_ A break-down of the individual costs is shown in the table below : |
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Cost |
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| Heat pumps, underwater pump & pipes : |
€19,600 |
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| Site civil works : |
€600 |
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| Electrical works and additional plumbing : |
€1,500 |
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| Total : |
€21,700 |
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| Benefits |
The installation of the heat pump systems has resulted in a number of positive impacts for the pool users, owners and for the environment :
- The centre’s heating costs have been reduced significantly compared to using the original LPG heating system. In addition to this, future energy cost increases will be minimised.
- Increased safety compared to using LPG direct-fired boilers. The heat pump systems can safely be left to run unattended overnight unlike the old LPG boilers.
- Pool users’ comfort has been increased by improved temperature conditions in the pool itself as well as the showers.
- The opening season of the pool centre can now be increased by up to an additional three months per year while still remaining economical.
- When the LPG boilers were operating, a significant amount of noise was generated. This disturbance has now been eliminated due to the silent operation of the heat pump systems.
- The heat pumps contribute to environmental protection by displacing emissions of CO2, sulphur oxides and oxides of nitrogen released with the combustion of LPG in the old boilers.
- As well as the specific emission reductions of this project, the project is also helping to generate awareness of environmental issues.
- The Bagenalstown Swimming Club has been shown to play a leadership role in sustainable energy use at both a local and national level.
_ The table below compares the energy consumption, energy cost and CO2 emissions of the old LPG boilers and the new water to water heat pump used to heat the pool water, based on an estimated heat requirement of 375kWh per day x 155 days = 58,000kWh per year :
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_ Note : costs include value added tax. The air to water heat pump, while not considered in this analysis, adds approximately 5% to the centre’s heat requirement and CO2 emissions.
- The automatic control system allows the heat pump to operate during the most cost effective hours using the ‘Night Saver’ electricity rate, i.e. day rate : 4 hours per day, night rate : 9 hours per day.
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_ Automatic control system
_ The table above shows the significant savings in energy cost, energy consumption and CO2 emissions resulting from replacing the LPG boilers with heat pumps.
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Partners&Roles |
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| Partnership details |
Carlow Leader Rural Development Company Limited provided grant assistance for the installation of the heat pump systems. Carlow Leader aims to encourage and support rural dwellers and community groups in Carlow to consider the long term potential of their areas in accordance with their own priorities.
_ The Carlow Kilkenny Energy Agency helped the swimming club to secure funding from Carlow Leader. The Agency was established to provide sustainable energy information and services to the people of Carlow and Kilkenny, to local businesses and community groups and to the local authorities.
_ Carlow County Council and Carlow Kilkenny Energy Agency have signed up to the Display® Campaign in order to analyse and improve the energy efficiency of public buildings in County Carlow. The Carlow Kilkenny Energy Agency particularly focused on public buildings as this is an effective means of raising energy awareness. |
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Recommendations |
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| Achievements |
Barriers encountered
The main barriers encountered in the planning and development of this project included :
- Perception of a limited availability of information and system providers for this technology compared to fossil fuel systems. To overcome this, Carlow Leader were able to suggest a number of possible suppliers and installers.
- Perception of increased risk compared to fossil fuel heating systems due to the limited number of existing local examples.
_ This barrier was overcome by examining European swimming pools using similar systems and Irish case studies of different building types using heat pumps.
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| Lessons Learned |
Repeatability
Water to water heat pump installations are limited to locations where a steady supply of water is available. Any building that is within reasonable distance of a river or lake or even an underground stream can easily incorporate this type of system either at the initial design stage or as a retrofit system.
_ Air to water heat pump systems offer a much wider potential for replication. Almost any building has the potential to be fitted with this type of system. They are especially suitable for buildings where a water source or sufficient land area for a ground source heat pump is not available. Air to water systems can also be applied to ventilation with heat recovery systems allowing recovered heat to be reused to its full potential.
_ Lessons for policy development
The success of this project serves as a good practice case study for any existing leisure facilities or other types of buildings that are looking to upgrade their heating system and for new buildings. This is especially relevant with the introduction of the EU Energy Performance of Buildings Directive, which requires that the feasibility of renewable energy sources be considered for certain new buildings.
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Useful info |
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| Publications |
“Bagenalstown Swimming Pool Good practice Case Study - Heatpump systems” prepared by Carlow Kilkenny Energy Agency |
| Websites |
www.ecoheat.ie
www.neura.at
www.carlowleader.ie
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| Arrangements to visit |
Contact The Carlow Kilkenny Energy Agency |
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