*Article* **Experimental Validation of Water Flow Glazing: Transient Response in Real Test Rooms**

**Belen Moreno Santamaria 1, Fernando del Ama Gonzalo 2,\*, Benito Lauret Aguirregabiria <sup>1</sup> and Juan A. Hernandez Ramos <sup>3</sup>**


Received: 16 June 2020; Accepted: 14 July 2020; Published: 16 July 2020

**Abstract:** The extensive use of glass in modern architecture has increased the heating and cooling loads in buildings. Recent studies have presented water flow glazing (WFG) envelopes as an alternative building energy management system to reduce energy consumption and improve thermal comfort in buildings. Currently, commercial software for thermal simulation does not include WFG as a façade material. This article aims to validate a new building simulation tool developed by the authors. Simulation results were compared with real data from a scale prototype composed of two twin cabins with different glazing envelopes: a Reference double glazing with solar-control coating and a triple water flow glazing. The results showed a good agreement between the simulation and the real data from the prototype. The mean percentage error of the indoor temperature cabin was lower than 5.5% and 3.2% in the WFG cabin and in the Reference glazing one, respectively. The indoor air temperature of the WFG cabin was 5 ◦C lower than the Reference one in a free-floating temperature regime when the outdoor air temperature was 35 ◦C and the maximum value of solar radiation was above 700 W/m2. WFG has energy-saving potential and is worthy of further research into the standardization of its manufacturing process and its ability to increase building occupants' comfort.

**Keywords:** building energy simulation; water flow glazing; experimental validation
