Before the installation of this additional Ductwork, these condensing units were performing unsatisfactorily due to the re circulation of air that needed to be expelled, and historically these systems would go into alarm having a dramatic effect on performance. After installation of these plenums we were keen to see the impact they would make to the systems and were overwhelmed with the results, with the client loosing over 50% of their cooling the previous summer we had now achieved 100% success in 40 degree heat. We would also like to thank Duct and Vent (Hertford) for their support with manufacture on this project.