Originally Posted by
172_driver
You can't set the cabin altitude specifically on that system. Before take off you tell the computer your cruise altitude and landing elevation. It works out the rest. I am thinking the OP could set a lower cruise altitude in the window. Below FL370 the max diff pressure is reduced slightly. That might relief some of the excess pressure inside. If so you'll end up with a higher cabin altitude. This is speculation on my part though, not sure if that is what will happen for real...
If you set a LOWER cruise altitude what does the pressurisation system do?