This checkbox enables autosizing for the water-source (or outdoor) unit, which can otherwise be manually sized if necessary to match specific manufacturer catalog data. It is recommended that autosizing be run prior to manual sizing such that a unit can be selected with capacity at least equal to or greater than the autosized capacity. The dialog will record the design conditions at which the peak load for autosizing occurred, which may also be useful in selecting VRF equipment for the project