A leading pharmaceutical company was in need of an Air Handling System to provide different Temperature and Relative Humidity conditions from single equipment. The requirements were as follows:
| Temperature , O C | Relative Humidity % |
| 65 | 8 |
| 55 | 12 |
| 40 | 25 |
| 25 | 70 |
This was a once-through system for tableting with all the air was exhausted. The challenge was to maintain any of the above conditions throughout the year – irrespective of the seasonal fluctuations in ambient conditions. For such applications dew point control works best. Air Handling Unit was designed to supply air at the lowest dew point in monsoon season and the highest dew point (moisture content) in winter. This ensured the equipment had capability to achieve any combination of Temperature and Relative Humidity between the two extreme conditions desired. The control system was engineered to optimize energy efficiency by ensuring dehumidification and humidification did not function simultaneously.