A refrigerator works between $4^{\mathrm{o }}\mathrm{C}$ and ${30}^{\mathrm{o}}\mathrm{C}$. It is required to remove $\text{600}$ calories of heat every second in order to keep the temperature of the refrigerated space constant. The power required is:

(Take $\text{1}$ cal = $\text{4}\text{.2}$ Joules)