Problem

A prominent junior college in Rhode Island urgently needed to replace a failed 35-year-old pool room dehumidifier. The dehumidifier manufacturer had gone out of business, and repair parts were no longer available.

This project presented a tough challenge: the 50-ton dehumidifier was installed in the basement when the pool room was built. There was no easy way to remove the existing system or position a new replacement unit. The college contacted its local DCA representative and DCA’s applications engineering team to tackle the problem.

DCA performed a moisture load study and determined that the failed system was oversized by approximately 20% for unknown reasons. This often happens when the pool surface area is reduced or the pool water temperature is changed, reducing the capacity for the dehumidification system.

Solution

Our team determined that the old system could be replaced with two DCA7000T 15-ton systems and a dedicated DCA4800T-OA 10.4-ton make-up air dehumidifier. (The DCA7000T may be compared with Desert Aire™ model number LC 15 or Dectron model number DS 080.) The two smaller 15-ton dehumidifiers would fit down the narrow stairway and through the double door of the mechanical room. The failed dehumidifier was cut into small pieces and carried out. The make-up air dehumidifier was installed in a small outdoor area next to the pool room.

The reasoning behind this solution was that by de-coupling the outdoor make-up air and providing the correct pool moisture removal capacity, two 15-ton systems would be adequate.

The twin 15-ton pool dehumidifiers provided additional advantages with their ability to be controlled individually by the building management control system. During periods of low pool usage, only one dehumidifier would operate. As occupancy increased, both systems could be energized. Calculations showed that this method would create a sizeable energy savings.

These dehumidifiers also feature hot water space heating coils and will accommodate pool room cooling through the outdoor cooling tower, thus eliminating the need for outdoor remote condensers.

The DCA4800T-OA make-up air dehumidifier would only operate as needed during warm, humid months. A small preheat duct heater was added to ensure make-up air temperatures would consistently remain above 70°F during cold months.

Results

This DCA system saved tens of thousands of dollars alone by avoiding expensive building modifications to gain access to the lower level mechanical room to install a large dehumidifier. Coupled with lower operating costs, this project came in under budget, and the college will realize savings for many years to come.

Find out more information on Replacement Dehumidifiers.