Innovative heating and cooling water terminal units for NZEB, ZEB and ZCB, designed to maximize reciclabilty of materials of energy efficient heat pumps comfort systems
In the future of heating and cooling comfort systems, we can expect a progression beyond the concepts of Nearly Zero Energy Buildings (NZEB), Zero Energy Buildings (ZEB) and Zero Carbon Buildings (ZCB). As these standards focus mainly on energy efficiency and carbon emissions, future generations of heating and cooling comfort systems will likely pursue even more ambitious sustainability goals, integrating a variety of comfort solutions including integrated fresh air management, circular economy principles and holistic approaches to environmental impact, with a special focus on a more rational use of materials. The water terminal units analysed in this paper, similar in principle to traditional fan coil units, are based on a water-to-air microchannel heat exchange technology, which is aimed not only at achieving high energy efficiency, but also to reach high level of recyclability of materials. This means that the relevant part (over 94% by weight) of the materials used in the water terminal unit described will be either renewable, reusable or recyclable. As fan coil units are generally emerging as a very valuable emission solution for heating and cooling, water-based heat pump comfort systems, the indoor comfort terminal units described in the present paper can provide these systems with additional value related to the rational use of materials, rather than simply maximizing their energy performance. In detail, the goal, considering the end-of-life cycle of fan coil units, is to try to eliminate waste as much as possible and keep materials in a closed loop, considering recyclability as a relevant parameter alongside energy efficiency. As sustainability and technology continue to evolve, and considering that significant progress has already been made, for example in terms of energy-efficient heating and cooling generation (e.g., through heat pump-based solutions) and intelligent controls (e.g., Smart Readiness Indicator – EPBD [1]), the expectation is that developments related to highly recyclable indoor water terminal units can play an increasingly active role in improving water-based heat pump comfort systems in the future, also facing to conscious use of materials. In this context, present paper focuses on the analysis of the relevant technical characteristics for indoor water terminal units used in water-based heat pump comfort systems, in order to meet the requirements of NZEB (Nearly Zero Energy Buildings), ZEB (Zero Energy Buildings) and ZCB (Zero Carbon Buildings) and to identify the most promising solutions in terms of energy efficiency and recyclability. Considering the significant growth, expected in the coming years, for water-based heat pump comfort systems and relative fan coil units, it is very important that research could move forward not only focusing of the heat pump units (heat generation), but also taking in proper account water terminal units (heat emission).