Duct split is one of the most common air conditioning systems in the world and is widely considered by builders of residential, commercial and office buildings. This system is one of the most economical and viable air conditioning systems that similar to other air conditioning systems include an internal unit (evaporator) that is covered with dropped ceiling. The internal unit transfers hot or cold air to independent environments through specific standard conduits. The external unit (condenser) consists of a compressor and coil with a suitable capacity outside of the building. For heating system in duct split, the warm water from the boiler house or heating package can be utilized. One of the important factors in duct split is the amount of energy they appropriately use that can be ideally used as a criterion for selecting a heating or refrigerating system.