Multi-criteria comparison of various drinking water installations for low-temperature supply systems in apartments

Rules to prevent from legionnaires disease gain importance as the building sector, esp. multi-family houses, needs to be decarbonized with temperature sensitive heat pumps. As legionella grow often in the peripheries of the pipe networks, we carried out dynamic simulations with TRNSYS of four different piping designs with composite pipes inside a reference apartment (T-piece, in-series, ring and a mix of T-piece for potable hot water (PWH) and ring for potable cold water (PWC)). We applied PWH and PWC tapping profiles for each tap, investigated two different supply temperatures of potable hot water 60 °C and 45 °C, and compared the results using hygienic, comfort and energy efficiency performance indicators. Based on the indicators and the boundary conditions used, classical T-piece and the mix installation show the best results, followed by series and ring, especially when using decentral water heaters with 45 °C

Strengths, weaknesses, opportunities and threats of demand response in district heating and cooling systems. From passive customers to valuable assets

Buildings can deliver short-term thermal energy storage by utilising the thermal capacity of the building construction and/or by activating the water tanks included in the heating/cooling installation. The flexibility potential of demand management using decentralized thermal energy storage has been quantified in many theoretical modelling studies, and it is considered an essential technology for an affordable energy transition. We have investigated the drivers and barriers to the adoption of demand management in buildings in district heating and cooling systems via a Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis and presented 17 elements that shape the current and future application of this concept. The results indicate that the application of the DR concept has left the theoretical studies and moved towards real-life applications. Yet, there is a lack of feasible business models and regulatory frameworks supporting the large-scale application of the concept. Utilities and their customers do not fully understand the benefits of the DR concept; therefore they are reluctant to adopt it outside of the research projects where the test environment is fully controlled and with limited impact and timeline. Therefore, the regulatory framework must be adjusted to allow DHC operators to develop new business models and DR tariffs that will incentivise the customers to deliver flexibility to the system without compromising their comfort and everyday practices and increasing energy poverty.</p

Neubau und Transformation hocheffizienter Wärmenetze im Kontext der Dekarbonisierung und Flexibilisierung unserer Energiesysteme

Fernwärme (FW) spielt aufgrund ihres Potenzials zur effizienten Integration erneuerbarer Energien (EE) und Abwärme eine entscheidende Rolle für die Umsetzung der Wärmewende. Im Rahmen dieses Beitrags werden Herausforderungen, Maßnahmen und Trends sowie Projektbeispiele für die künftige Fernwärmeversorgung beleuchtet