Determination of Dehumidification Capacity of Water Wall with Controlled Water Temperature: Experimental Verification under Laboratory Conditions

Abstract

Water elements with flowing water on the surface are common in buildings as a form of indoor decoration, and they are most often perceived as passive humidifiers. However, by controlling water temperature, they can be also used for air dehumidification. The dehumidification capacity of indoor water elements was investigated experimentally under laboratory conditions. For the experimental verification of dehumidification capacity, a water wall prototype with an effective area of falling water film of 1 m2 and a measuring system were designed and developed. A total of 15 measurements were carried out with air temperatures ranging from 22.1 °C to 32.5 °C and relative humidity from 58.9% to 85.6%. The observed dehumidification capacity varied in the range of 21.99–315.36 g/h for the tested measurements. The results show that the condensation rate is a dynamic process, and the dehumidification capacity of a water wall strongly depends on indoor air parameters (air humidity and temperature). To determine the dehumidification capacity of a water wall for any boundary conditions, the equations were determined based on measured data, and two methods were used: the linear dependence between humidity ratio and condensation rate, and nonlinear surface fitting based on the dependence between the condensation rate, air temperature, and relative humidity.

Design and Evaluation of Building Structures Planned for Harsh Conditions

“…They publish the results in magazines. The latest publication from the year 2021 is in the journal Sustainability [9].…”

The Synergy of Living and Water Wall in Indoor Environment—Case Study in City of Brno, Czech Republic

“…As living walls, water features such as fountains and pools but also vertical water features are more and more commonly parts of building interiors, especially for their decorative character. However, compared to green walls, the effect of water elements on physical parameters of the indoor environment has not been sufficiently investigated [44]. The design of water elements in the interior may vary, either in shape or material.…”

“…On the other hand, there is an assumption that with the regulation of the temperature of the water flowing in the system, it is possible to use the water wall with greater flexibility and adapt its use to the state of the air in the indoor environment [49]. If the water in the system is cooled below the air dew point, condensation will occur, dehumidifying the air in the room [44,50]. Conversely, if the water in the system is heated and maintained at a stable temperature, which will be similar to the air temperature, evaporation will occur, which will increase the humidity, and at the same time, the air in the indoor environment will not be cooled [51].…”