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?

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

$3.$ What COPr can we expect?