Mold channels and runners refer to the openings in the mold that allow the molten plastic to be injected. There are also specific channels dedicated to aid in cooling the mold. The most time consuming aspect of injection molding is cooling time. By pumping coolant into the mold channels heat is more quickly dissipated. This drastically cuts production time by freeing the product from the mold quickly, allowing rapid product production. The typical coolants pumped into these channels are water, ethylene glycol, or a mixture of the two. The inlet opening is where the coolant enters and is then pumped through the mold channels absorbing heat along the way to the outlet. The hot coolant is routed from the outlet where it can be circulated through the chiller system. Once it is cooled the refrigerant can cycle through the mold again.