Carbon Calculator How much carbon can you save by switching to a Zero Power Cooling System? Use the calculator to work out your carbon saving based on retrofitting the Zero Power Cooling System versus traditional chillers to your emergency tank showers. Simply enter the number of tank showers you have or plan to purchase and see the carbon savings in kilograms.  Number of tank showers with chillers: So what do these figures equate to? 30,000 â€...