A PVDC film manufacturing plant located near Pune had a requirement of air conditioning with high RH to prevent wrinkling of the film during the manufacturing process. An air conditioning company was awarded the
contract to supply and install the system which comprised of air handling capacity of 68,000 cubic meters per hour (40,000 CFM). As the conditioned area was to be certified for Class 1,00,000 conditions, some fresh air was introduced in the AHU. However, as Pune has hot and dry ambient during the summer and low ambient temperatures during the winter, humidification of fresh air was necessary to raise the space RH. Unfortunately, the air conditioning company had completely overlooked this aspect and was struggling with the system to achieve the desired room RH, especially during the winter. The client suffered heavy losses due to material rejections. A couple of humidifying options were considered and two of them were employed. The client did not have any steam source available, which ruled out live steam or steam-to-steam humidifiers. A resistive steam humidifier was added to achieve the desired RH level during the summer and winter. Subsequently, to improve the cooling effect of the installed air conditioning system, jet spray nozzles were installed in the conditioned space. This not only humidified the area but also provided additional cooling.