Final Report Summary - LOW-HEAT (The Development of a new Domestic Heat Recovery Technology for Low Grade Heat in Waste Water)
Hot water is a commodity in western societies; however its preparation and storage are energy consuming activities of significant cost. Changes in legislation due to environmental concerns, along with the necessity for implementation of sustainable management techniques in heating and plumbing rendered the development of new solutions necessary.
Low-grade temperature wastewater heat recovery could form a viable option, since wastewater could be exploited as a pre-heat for various applications to reduce their energy requirements. Nevertheless, conventional heat exchangers are not suitable for such applications under low-flow conditions, due to low thermal efficiency. In addition, wastewater contains dissolved chemicals, organic and solid matter which could result in fouling and odours and reduce the system efficiency and life span.
The LOW-HEAT project aimed to overcome these difficulties and develop a low cost and efficient intelligent network management of heat recovery devices for the plumbing and heating market. The proposed system supplemented boilers and was able to recover up to 50 % of the wasted heat energy, thus effectively reducing energy consumption and CO2 emissions in buildings. The product was planned to provide an economic return of 24 months or less if applied in the commercial and domestic sector. The creation of new job opportunities in the heating and plumbing market was also among the solution benefits.
The developed system consisted of three components, namely a heat exchanger, a drain device and a radio frequency (RF) controller. The heat energy was captured from warm waste via the heat exchanger and was redirected to a hot water system. The product structure secured that no contamination of the heated water was possible, in accordance with legislation demands.
The system pump was automatically activated when wastewater of temperature higher than 30 degrees Celsius was detected. In addition, the software incorporated within the device was capable of clearing blockages located in the filter by reversing the pump action. The heat pipe was innovative since it did not contain any moving parts and did not rely on any external power apart from the thermal loading. Finally, the RF controlled provided to the end user information related to cost and energy savings and maintenance requirements.
Two heat exchanger concepts were designed, manufactured and tested to achieve the highest possible heat transfer rate. The in-line proposal was the most effective and was therefore promoted for the final system. Nevertheless, the alternative solution was not excluded as a potential option. Furthermore, the pipe design was thoroughly examined in an attempt to reduce production costs.
The elaborated cost analysis proved that a fully operational system was anticipated to have a payback of approximately four years. This was behind the initially set target, but formed a competitive and viable proposal in comparison to commercial alternatives.
The project included numerous dissemination activities for marketing purposes, such as the development of a project website, the production of a digital video disk (DVD), the participation in local events and the publication of magazine articles. Patenting the technology allowed for the inclusion of further details regarding the proposed innovations in the dissemination material. The potential for further development and exploitation of LOW-HEAT outcomes was recognised across Europe and resulted in an award for energy efficiency which was welcomed by the project members.
Low-grade temperature wastewater heat recovery could form a viable option, since wastewater could be exploited as a pre-heat for various applications to reduce their energy requirements. Nevertheless, conventional heat exchangers are not suitable for such applications under low-flow conditions, due to low thermal efficiency. In addition, wastewater contains dissolved chemicals, organic and solid matter which could result in fouling and odours and reduce the system efficiency and life span.
The LOW-HEAT project aimed to overcome these difficulties and develop a low cost and efficient intelligent network management of heat recovery devices for the plumbing and heating market. The proposed system supplemented boilers and was able to recover up to 50 % of the wasted heat energy, thus effectively reducing energy consumption and CO2 emissions in buildings. The product was planned to provide an economic return of 24 months or less if applied in the commercial and domestic sector. The creation of new job opportunities in the heating and plumbing market was also among the solution benefits.
The developed system consisted of three components, namely a heat exchanger, a drain device and a radio frequency (RF) controller. The heat energy was captured from warm waste via the heat exchanger and was redirected to a hot water system. The product structure secured that no contamination of the heated water was possible, in accordance with legislation demands.
The system pump was automatically activated when wastewater of temperature higher than 30 degrees Celsius was detected. In addition, the software incorporated within the device was capable of clearing blockages located in the filter by reversing the pump action. The heat pipe was innovative since it did not contain any moving parts and did not rely on any external power apart from the thermal loading. Finally, the RF controlled provided to the end user information related to cost and energy savings and maintenance requirements.
Two heat exchanger concepts were designed, manufactured and tested to achieve the highest possible heat transfer rate. The in-line proposal was the most effective and was therefore promoted for the final system. Nevertheless, the alternative solution was not excluded as a potential option. Furthermore, the pipe design was thoroughly examined in an attempt to reduce production costs.
The elaborated cost analysis proved that a fully operational system was anticipated to have a payback of approximately four years. This was behind the initially set target, but formed a competitive and viable proposal in comparison to commercial alternatives.
The project included numerous dissemination activities for marketing purposes, such as the development of a project website, the production of a digital video disk (DVD), the participation in local events and the publication of magazine articles. Patenting the technology allowed for the inclusion of further details regarding the proposed innovations in the dissemination material. The potential for further development and exploitation of LOW-HEAT outcomes was recognised across Europe and resulted in an award for energy efficiency which was welcomed by the project members.
