At one of our clients' production facilities, there were 7 air handling units aimed at providing the thermal comfort of the rooms and adequate air exchange in the production halls. Each central station was equipped with a 150 kW water heater. The air handling units were relatively new and each had insulated ventilation ducts. In spite of that, it was an interesting area to improve energy efficiency.
In order to improve the ventilation comfort in the ventilated rooms and to reduce the consumption of thermal energy for the purpose of heating, the Auditor recommended replacing the supply stations with the supply and exhaust air handling units.
New units should be equipped with heat recovery, which will reduce the consumption of thermal energy. Potential savings were related with a system which would draw the air from the outside of facility in winter time, rather than from the inside of the hall. Assuming 67% heat recovery efficiency and the air temperature inside the hall of 20 ° C, the amount of energy that can be saved over the year was estimated.
Due to the modernization, 2.55 MWh of energy was saved and the cost-cutting reached the level of USD 60.7 thousand, with investment outlays of USD 121 thousand.