Drain Water Heat Recovery in Domestic and Commercial Settings

Much of the energy consumed in heating water for domestic appliances and sanitation is wasted to the drainage system. This waste not only exists in the domestic sector, but also applies to many commercial buildings such as hotels, schools, hospitals or leisure centres. The energy efficiency of such processes can be improved through the adoption of drain water heat recovery (DWHR) systems, as hot waste water passes through a heat exchanger and the heat energy is transferred to incoming cold water streams or to a hot water storage system.

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Determining the potential impact of DWHR technology

A desk study will quantify the potential for energy recovery using DWHR systems in domestic and commercial settings. This will enable a market assessment for DWHR systems, highlighting the potential for new business activity and growth using this technology.


Lab-scale development of DWHR units

Prototype DWHR systems will be developed to recover the heat in waste water from a whole dwelling in domestic and commercial settings. These systems shall comprise a waste heat holding tank and heat exchanger, together with a smart control system to optimise this complex energy recovery process.

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Field demonstration of DWHR in the hospitality sector

Field-scale demonstration sites of the developed technology will subsequently be deployed in both Ireland and Wales to demonstrate the potential for energy recovery in domestic and commercial buildings. This task shall comprise the design, installation and monitoring of the system over the long-term (adopting an eco-design approach from WP4.3). Energy savings and CO2 emissions reduction will be monitored. The site will again be used for site visits and case study work in the smart specialisation cluster.