Sustainability 2020, 12, 7564; doi:10.3390/su12187564 www.mdpi.com/journal/sustainability Article Industrialization and Thermal Performance of a New Unitized Water Flow Glazing Facade Belen Moreno Santamaria 1 , Fernando del Ama Gonzalo 2, *, Danielle Pinette 2 , Benito Lauret Aguirregabiria 1 and Juan A. Hernandez Ramos 3 1 Department of Construction and Architectural Technology, Technical School of Architecture of Madrid, Technical University of Madrid (UPM), Av. Juan de Herrera 4, 28040 Madrid, Spain; belen.moreno@upm.es (B.M.S.); benito.lauret@upm.es (B.L.A.) 2 Department of Sustainable Product Design and Architecture, Keene State College, 229 Main St., Keene, NH 03435, USA; pinetteda@gmail.com 3 Department of Applied Mathematics, School of Aeronautical and Space Engineering, Technical University of Madrid (UPM), Plaza Cardenal Cisneros 3, 28040 Madrid, Spain; juanantonio.hernandez@upm.es * Correspondence: fernando.delama@keene.edu Received: 9 August 2020; Accepted: 11 September 2020; Published: 14 September 2020 Abstract: New light envelopes for buildings need a holistic vision based on the integration of architectural design, building simulation, energy management, and the curtain wall industry. Water flow glazing (WFG)-unitized facades work as transparent and translucent facades with new features, such as heat absorption and renewable energy production. The main objective of this paper was to assess the performance of a new WFG-unitized facade as a high-performance envelope with dynamic thermal properties. Outdoor temperature, variable mass flow rate, and solar radiation were considered as transient boundary conditions at the simulation stage. The thermal performance of different WFGs was carried out using simulation tools and real data. The test facility included temperature sensors and pyranometers to validate simulation results. The dynamic thermal transmittance ranged from 1 W/m 2 K when the mass flow rate is stopped to 0.06 W/m 2 K when the mass flow rate is above 2 L/min m 2 . Selecting the right glazing in each orientation had an impact on energy savings, renewable energy production, and CO2 emissions. Energy savings ranged from 5.43 to 6.46 KWh/m 2 day in non-renewable energy consumption, whereas the renewable primary energy production ranged from 3 to 3.42 KWh/m 2 day. The CO2 emissions were reduced at a rate of 1 Kg/m 2 day. The disadvantages of WFG are the high up-front cost and more demanding assembly process. Keywords: building energy management; water flow glazing; unitized facade 1. Introduction The residential and commercial building sector accounts for almost 40% of the European Union final energy consumption [1]. Thus, the goal of achieving a highly energy-efficient building stock by 2050 was set by The Energy Performance of Buildings Directive (EPBD 2018) [2]. In the United States, recent studies have shown that heating and cooling account for more than 30% of energy consumption in buildings [3]. Other non-OECD countries, including China and India, will be responsible for half of the global increase in energy consumption until 2040 [4]. The development of new materials, new heating and ventilation technologies, and energy-saving measures have improved the thermal performance of buildings in winter conditions [5]. However, in summer conditions, the increasing standards of life and the affordability of air-conditioning technologies have contributed to increasing the energy needs for cooling over the last decade [6]. Nowadays, air conditioning in office and commercial facilities accounts for 15% of the total electricity consumption