QUESTION $2$

$2\mathrm{.}1$ The storage size $V_{\text{s}\text{t}\text{e}\text{r}\text{a}\text{g}\text{y}}$ for domestic hol water is twice the total requirements of persons $(P)$ with a daily requirement $V_{persen}$ por person.

Based on the hot water requirement $Q_{\text{p}\text{e}\text{r}\text{r}\text{a}\text{n}}$ per person per day, for a four$-$person househald with an werage consumption of $45$ itires or $1\mathrm{.}8$ kWh of hot water per day.

$($a$)$ calculate the storage size $V_{\text{s}\text{t}\text{e}\text{r}\text{a}\text{g}\text{t}}$ in litres

$($b$)$ the annual hot water requirement $Q_{hw}$ in kWh

$($c$)$ If the annual solar radiation is $H_{\text{s}\text{o}\text{t}\text{a}\text{r}}=1000\frac{kwh}{m^2},$ annual solar fraction $s_f=0\mathrm{.}9,$ tit gains $f_{\text{e}\text{r}\text{i}\text{m}\text{e}\text{t}\text{a}\text{t}\text{i}\text{o}\text{n}}=110\%$ and colector efficiency is $n_c=30\%,$ using the relationship below, calculate the colector size

$A_c=\frac{s_g{Q}_{\text{h}\text{u}\text{r}}}{{}_c{H}_{\text{s}\text{o}\text{l}\text{a}\text{r}}{f}_{\text{e}\text{r}\text{i}\text{e}\text{n}\text{c}\text{a}\text{r}\text{i}\text{o}\text{n}}}$

$($d$)$ If the effective area of this solar panel in $2\mathrm{.}1($c$)80\mathrm{.}8\frac{m^2}{?}$ piece, estimate the number of pioces of solar panel that should be installed to collect this heat demand.

$2\mathrm{.}2($a$)$ If this farnily with $4$ members plans to instal a solar water heater which is mainly used for bath and the hot$-$water temperature required for bath is $50C.$ while the annual average temperature of cold water is $23C.$ estmate the heat that should be provided by the solar water heater to satisfy the famly's demand for bath.

$(2)$

$3$

$($b$)$ if there is a centain solar panel with effective area of $0\mathrm{.}8m^2$ jpece which can offer solar panel and the number of picces naeded