A $$factory smokes $2500$ kg of bacon that is cooled to about $15$celsius and must be frozen down to $-1$ celsius in $3\mathrm{.}5$hours$.$

The factory wishes to install $2$ cooling units to carry out the task.

$1.$What total cooling effect is required on both units to complete the task? Do you take the time into consideration in this question?

$2.$Can CO$2$be used as refrigerant in a closed circuit for the task?

$3.$What COPr can we expect?