Water chillers: We recommend pumps between 500 gph and 1,800 gph to achieve a minimum flow rate of 250 gph.  Submersible pumps are commonly used for their simplicity. Pump size should compensate for factors like pipe length, fittings, and head height, so Penguin Chillers offers Danner water pumps ranging from 500 gph to 3600 gph. Glycol chillers: Space limitations might restrict pump options, so Penguin Chillers recommends specific glycol pump lines that work well with their units. Commercial water chillers: A measurable flow rate of 1,200 gph to 2,500 gph is recommended, but the pump size can vary depending on the application.