This work deals with implementation and analysis of Split HVAC System having automatic CO2 level adjustment through fresh air arrangement and Reverse Cycle (Heat Pump) features in the class rooms of school premises. Carbon-dioxide sensors have been used as part of a demand controlled ventilation (DCV) system for room requiring mechanical ventilation, and their performance can significantly impact energy use in these systems. The basic working principle of Air conditioning system, reverse cycle feature and NDIR CO2 sensors have been discussed. A survey has been conducted by various authors on the HAVC systems of classrooms of various colleges is also reviewed.