To determine the size of chiller you’ll need for your plastic process cooling application, follow this formula:

1. Calculate the pounds of material per hour being processed.
2. Determine how many pounds per hour are required for each ton of cooling capacity on Chart 1.
3. Determine if the extruder or any auxiliary equipment will require chill water. If not, go to step #6.
4. Size the equipment cooling capacity based on Chart 2 and Chart 3.
5. Combine the process and equipment cooling requirements.
6. Size your chiller by rounding up to the closest standard unit.

For example, what size chiller is needed for a polypropylene molding operation that incorporates a 6oz. "Shot Size" and a 18 second cycle time with a 3 H.P. hydraulic motor?

1. 6oz. / 18sec. = 19.99 oz/min (20.00 oz./min) 20 oz. / min x 60 min. = 1200 oz/hr 1200/16 = 75 lbs. / hr
2. Polypropylene requires 1 ton of cooling capacity for every 35 lbs./hr processed 75 lbs. ÷ 35 lbs. = 2.14 tons of cooling
3. A hydraulic motor requires 1 ton/HP of cooling capacity
4. 3 HP x .1 ton/HP = .3 ton of capacity
5. Combine process & auxiliary cooling requirements 2.14 tons + .3 ton = 2.4 tons
6. This application will require a 3-ton unit