Lake and river at heart of total-energy project
At the heart of a range of energy-efficient technologies at the Salmon Lake Centre and Ballecregga Tea Rooms on the Isle of Man is a Mitsubishi Electric City Multi WR2 heat-pump system that uses the salmon lake as a source for heating and to reject heat when cooling. Electricity for the system is provided by a 10 kW turbine in the nearby Laxey river. The project won an award for the best innovation in the private sector of the Isle of Man’s energy awards for 2015.
The site now benefits from a self-sufficient hydro-electric, central-heating, air-conditioning and hot-water system which can all be controlled centrally from a PC or remotely by smart phone or table.
Specialist building contractor SCS rose to the challenges using imaginative technologies and methodologies to create the project.
SCS called upon the expertise of HVAC specialist supplier Kooltech. A subsequent site visit determined that if the client used the natural resource of the adjacent salmon lake, far more benefits could be gained.
Alan Clarke, application engineer with Kooltech, explains, ‘One of the biggest concerns on a project such as this is the dissipation of heat that can be generated from a system, so the logical solution was to use the salmon lake. The benefit of using the lake was that the system wouldn’t be at the mercy of the elements or have to worry about heat dissipating into the atmosphere.’
The closed loop WR2 heat-pump system provides heating and cooling, with heat exchange to the lake water via a ‘slinky’ coil at the bottom of the lake. The lake provides the heat source for space heating and accepts rejected heat from cooling. The temperature of the lake is around 17°C in summer and 5°C in winter.
The WR2 system uses wall-mounted units to heat or cool open-plan area and the cafe.
The next stage was to install a PWFY heat-pump boiler as a primary heat source to meet the requirements for sanitary hot water, underfloor heating and central-heating. It takes rejected heat from air conditioning to supply hot water for the kitchen.
Discreet remote temperature sensors were commissioned in each room, and a TG-2000 control software system was installed on a central computer connected to a bespoke K-Con control panel developed by Kooltech.
Alan Clague of SCS summarises, ‘Although the site is connected to the grid, the turbine generates 10 kW of electricity, so this means that other than the original capital, there are not other costs involved in the whole project.’