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


Received: 19 July 2020; Accepted: 11 September 2020; Published: 15 September 2020

**Abstract:** Large glass areas, even high-performance glazing with Low-E coating, could lead to discomfort if exposed to solar radiation due to radiant asymmetry. In addition, air-to-air cooling systems affect the thermal environment indoors. Water-Flow Glazing (WFG) is a disruptive technology that enables architects and engineers to design transparent and translucent facades with new features, such as energy management. Water modifies the thermal behavior of glass envelopes, the spectral distribution of solar radiation, the non-uniform nature of radiation absorption, and the diffusion of heat by conduction across the glass pane. The main goal of this article was to assess energy consumption and comfort conditions in office spaces with a large glass area by using WFG as a radiant heating and cooling system. This article evaluates the design and operation of an energy management system coupled with WFG throughout a year in an actual office space. Temperature, relative humidity, and solar radiation sensors were connected to a control unit that actuated the different devices to keep comfortable conditions with minimum energy consumption. The results in summer conditions revealed that if the mean radiant temperature ranged from 19.3 to 23 ◦C, it helped reduce the operative temperature to comfortable levels when the indoor air temperature was between 25 and 27.5 ◦C. The Predicted Mean Vote in summer conditions was between 0 and −0.5 in working hours, within the recommended values of ASHRAE-55 standard.

**Keywords:** building energy management; Water Flow Glazing; mean radiant temperature; final energy consumption
