HVAC (Heating, Ventilation and Air conditioning) system is one of the important aspects in project management of commercial and industrial buildings. In tropical country like India, for commercial applications, the emphasis is more on air conditioning compared to heating and ventilation. The commissioning activity of air conditioning system is very exhaustive and critical in ensuring required comfort conditions at lowest operating cost. The present paper discusses some of the important aspects in balancing of air conditioning system. The lessons learned are compiled for ready reference to the architects, consultants, contractors, project managers and end users.