What is HY-DRY®
Most people feel most comfortable in the summer when the temperature is between 20°C to 23°C (69F and 73F), and the relative humidity is between 35% and 55%. Many air conditioning systems in high humidity areas cannot provide these temperature-humidity conditions. The HY-DRY® technology is an affordable method to increase the moisture removal capabilities of direct expansion air conditioning systems by as much as 70%.
As a result of the enhanced moisture removal, “cold and clammy” buildings will be comfortable, cool and dry. In addition, the humidity in the supply ductwork is significantly lower with the HY-DRY system, so that indoor air quality problems resulting from bacteria and mold in supply air ducts are reduced or eliminated. HY-DRY can also improve the moisture removal performance of refrigeration and industrial process air cooling equipment.
The key elements of the patented HY-DRY technology are the LPA® Liquid Delivery Pump and the HY-DRY® coil, both of which can be specified in new air conditioning equipment or retrofit to existing systems. Only minor additions to system controls are required in most cases. The HY-DRY coil has a very low air side pressure drop, so no changes to the indoor fan system are required.
HY-DRY De-humidification Theory
The HY-DRY® coil is a finned tube heat exchanger in the liquid line between the LPA® Pump and the Thermostatic Expansion (TEV) or Electronic Expansion Valve (EEV), and is located downstream of the evaporator coil on direct expansion (DX) air conditioning systems. The coil performs two important functions simultaneously. The liquid entering the TEV is sub-cooled by as much as 25°C (50F), which increases evaporator capacity, enabling the evaporator to remove as much as 70% more moisture from the air. At the same time, the air leaving the evaporator is reheated slightly which lowers the relative humidity in the supply ductwork. The effect of the additional subcooling on evaporator capacity is shown on the attached pressure enthalpy diagram (Fig. 1).
