The TAF-L-V is a variable linear bar diffuser plenum for underfloor perimeter supply applications. The TAF-L-V cooling plenum has an engineered throw pattern that never breaks through the stratification layer created by the UFAD diffusers in the core. The dual aperture plate design allows the TAF-L-V/CT-TAF-L assembly to maintain this engineered throw pattern while modulating the airflow volume. This model can help contribute toward achieving LEED Credits.