## 1 Introduction  
The agricultural sector is facing numerous obstacles nowadays. Growing population causes increasing need for food supply, while facing the effects of climate change. The resources available on Earth are increasingly limited, the degradation of agricultural land is progressing, and the pollution of the atmosphere, soil, and water is becoming more visible [1]. Various solutions are implemented worldwide to achieve progressive agricultural sustainability. One of the key examples is food production in vertical farming in ecosystems created in internal spaces (e.g., production hall) [2]. Closed ecosystems allow for maintaining the environment parameters (e.g., air temperature and relative humidity) that are best for plant growth, which would not be possible in conventional outdoor cultivation. The fundamental principles of this method are plant cultivation on several levels (obtained e.g., by using prefabricated modules) and control of indoor environment parameters (temperature, light, relative humidity, and gases). This is essential for yield maximization in a limited space all year round [3]. It also enables farming in places such as a skyscraper, shipping container, or warehouses [2]. Vertical food production might be further increased by using soilless type of cultivation: hydroponics or aeroponics. The common feature of these types of cultivation is the fact that water supplies nutrients to the root zone. In hydroponics, the root zones of plants are located in the water, while in aeroponics the roots are sprayed with mist containing nutrients at appropriate time cycles [4]. The water not used by plants can be recirculated in both, hydroponics and aeroponics. The concept of cultivation in closed environment has been studied since the early 1960s, when the first space missions and long-term Antarctic expeditions appeared [5; 6]. A review of over 46 plant production facilities in Antarctic has been described in detail in [PERSON] et al. (2015) [5]. The second area where closed environment systems have been tested is the space sector. [PERSON] (2017) [7] has listed the most important experiments. In both fields, a large proportion of systems used in experiments were hydroponics e.g., BIOS-3 experiment (hydroonic cultivation of grain, vegetables, oil crop (63 m\({}^{2}\))) [8], ILSSTF experiment (hydropionic cultivation of grain and vegetable (11.9 m\({}^{2}\))) [9], CEEF experiment (hydroponic and solid media cultivation of grains, vegetables, oil crop (150 m\({}^{2}\))) [10], Space Ecosystem I experiment (hydroponic cultivation of vegetables (36 m\({}^{2}\))) [11], and SMC experiment (hydroponic and solid media cultivation of wheat and vegetables (4.4 m\({}^{2}\))) [12]. The experience gained from these experiments, although carried out in relation to space-based applications, has shown that such solutions can also be applied to the terrestrial agriculture industry. In fact, there are many examples of vertical farming facilities all around the world. Recent extensive reviews of working facilities are presented in literature [4; 13; 14]. Recently a systematic bibliographical review on different approaches and applications of sustainable urban farming (including vertical cultivation) was made by [PERSON] and [PERSON] (2020) [15] who analyzed techniques and equipment used, the energy requirements, distribution, and solutions to decrease costs of this sector, and optimization techniques of the cultivation possibilities. It can be seen that water effectiveness is a very important area. Although, the hydroponic system is itself very water efficient, it may be further enhanced by the application water recovery from the air (the condensate). The authors report the possibility of condensation of water from air on a cooling coil panel in an air conditioner [15]. The different approaches are also considered. In fact, water recovery from air might be performed in various ways. It might include use of a typical air-conditioning unit or recuperative exchangers, depending on the location of the cultivation hall.