Turn on the Supply fan and rotate the speed control until there is only a very small negative pressure within the building. You can easily check the pressure differential with any source of smoke such as a cigarette or match held near a nearby opening to the outside. The smoke should lazily move into the building. You can also check this adjustment at the edge of the AlderHood. Simply place your source of smoke near the bottom front or rear edge of the AlderHood and watch what happens.
Proper balance is achieved when the smoke initially travels downward and then spirals inward.
Of course, with experience, you will learn how to adjust your AlderHood to suit your preferences. During bitter cold weather, you might slightly slow down both the exhaust and supply air in order to better temper the incoming air. We welcome your comments, suggestions, etc.