Aprilaire offers flexibility for all your zone control applications by providing you with all the features you demand. Accounting for excess system pressure is a requirement of any zone control system and we know there are many options for pressure relief. That is why Aprilaire supports all the popular options. You can choose from Aprilaire's exclusive 'Controlled Pressure Relief' method (which requires no bypass damper), using a bypass damper along with plenum temperature control or choosing to bypass to a dump zone.