## 3 Results and Discussion
### Heating  
We consider the adsorptive heating cycle for the domestic production of warm water with the temperature \(T\)uh = 45 \({}^{\circ}\)C suitable for dishwashing, cooking, and showering during the warm season (May-September). This is relevant for countryside summer houses, which are very popular in Russia. At heating mode, \(T\)ev equals the daily temperature \(T\)d.av averaged over each month. The useful heat is produced in a condenser during regeneration and in an adsorber during adsorption stage. The condenser and adsorption temperatures equal the temperature of the useful heat required to the consumer (\(T\)con = \(T\)ads = \(T\)uh). The boundary adsorption potentials \(\Delta F_{1}\) and \(\Delta F_{2}\) are calculated for water as the working fluid by Equations (1) and (2) for \(T\)reg varying from 75 to 90 \({}^{\circ}\)C (Table 2). Composites--LiCl/Verm and LiCl/MWCNT, MOFs--MIL-125-NH\({}_{2}\) and CAU-10, and FAM-Z01 appear to be the most promising for the heating mode, with the amount of cycled water \(\Delta w\) varying from 0.1 to 0.9 g/g for different locations and months (Table 2). For Vladivostok, water heating up to the temperature \(T\)uh = 45 \({}^{\circ}\)C is realistic from May to October, but for other zones, only during the summer months (Table 2). The minimum regeneration temperature \(T\)reg depends on the conditions during adsorption stage and the \(\Delta F_{2}\)-value. For example, in Oimyakon (zone IV), with low ambient temperature (\(T\)ev), an adsorbent with quite strong affinity is required (\(\Delta F_{2}\) = 4.2-4.8 kJ/mol (Table 2)) to get useful heat at \(T\)uh = 45 \({}^{\circ}\)C. A temperature of 75 \({}^{\circ}\)C is not enough to drive the cycle, even in summer (Figure 5), because the calculated potential during the adsorption stage is higher than the potential during desorption stage (\(\Delta F_{2}\) > \(\Delta F_{1}\)). This means that regeneration of any studied adsorbent under such conditions is impossible.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**City** & **Treg, \({}^{\circ}\)C** & \(\Delta F_{2}\)**, kJ/mol** & \(\Delta F_{1}\)**, kJ/mol** & \multicolumn{2}{c}{\(\Delta w\)**, g/g**} & **Period** \\ \hline \multirow{4}{*}{Astrakhan} & 90 & \multirow{4}{*}{2.5–3.8} & 6.2 & LiCl/Ver & 0.6–0.9 & \multirow{4}{*}{May–Sept} \\ \cline{3-5}  & & & & LiCl/ MWCNT & 0.3–0.5 & \\ \cline{2-5}  & 85 & & 4.8 & MIL125 NH2 & 0.3–0.4 & \\ \cline{2-5}  & 75 & 2.5–2.9 & 4.1 & FAMZ01 & 0.2 & \\ \cline{2-5}  & 90 & 3.7–5.0 & 6.2 & LiCl/Ver & 0.5–0.6 & May–Sept \\ \cline{2-5}  & 80 & 3.7–4.0 & 4.8 & CAU10 & 0.3 & \\ \cline{2-5}  & & & MIL125 NH2 & 0.2–0.4 & \\ \hline Vladivostok & 90 & 3.5–5.4 & 6.2 & LiCl/Ver & 0.4–0.6 & May–Oct \\ \hline \multirow{2}{*}{Omsk} & 90 & 3.4–5.0 & 6.2 & LiCl/Ver & 0.4–0.6 & May–Sept \\ \cline{2-5}  & 80 & 3.4–4.0 & 4.8 & MIL125 NH2 & 0.2–0.4 & Jun–Aug \\ \hline \multirow{2}{*}{Arkhangelsk} & 90 & 4.1–4.7 & 6.2 & LiCl/Ver & 0.4–0.6 & Jun–Aug \\ \cline{2-5}  & 90 & & 6.2 & LiCl/Ver & 0.6 & \\ \cline{2-5}  & 80 & 3.5–4.1 & 4.8 & CAU10 & 0.3 & Jun–Aug \\ \cline{2-5}  & 80 & & & MIL125 NH2 & 0.2–0.4 & \\ \hline Oimyakon & 90 & 4.2–4.8 & 6.2 & LiCl/Ver & 0.5–0.6 & Jun–Aug \\ \hline \hline \end{tabular}
\end{table}
Table 2: The boundary conditions of the heating cycles, the promising adsorbents, and the amount of exchanged water.