Universal systems for mounting HVAC components within an HVAC system where the component mounting system defines a platform comprised of slidingly engaging rail sections. Each of the rail sections include support brackets, from which, in some examples, extend a receiving member or an inserting member configured to engage a receiving member or an inserting member of an adjacent rail section. In particular embodiments, platform sections include arms having channels and arms having glides each glide being configured to slidingly engage the channel of an adjacent platform section allowing platform sections to adjust the effective length and width of the platform.