Multiple dehumidification units allowed for scheduled downtime while maintaining this underground spa’s precise humidity requirements.

The Grove Park Inn Resort & Spa is nestled in the Blue Ridge Mountains of Asheville, NC. It has long been a favorite vacation destination for much needed R&R and romantic getaways, especially during the hot southern summer season. Words cannot fully explain the beauty, size, and opulence of The Grove Park Inn; one must experience the many rooms, restaurants, and balconies first-hand to really appreciate the craftsmanship and attention to detail. It’s easy to see with a pedigree as long as theirs why service and ultimate satisfaction are at the top of the inn’s must-do list.

Jaime Huffman, executive spa director, said The Grove Park Inn needed significant repairs right after WWII. During the war, the Inn had worked with the U.S. government to house foreign diplomats, wounded seamen, and returning combat soldiers. The Sammons Corporation of Dallas purchased the resort in the 1950s and soon had the inn fully restored. Two wings were later added for a total of 512 rooms plus an assortment of craft and meeting rooms, world class dining, shopping areas, and of course, the spa.

Huffman gave the credit for the spa’s world class rating to Elaine D. Sammons who took the leadership role after her husband passed on. “Mrs. Sammons announced in 1998 that she wanted to build the finest resort spa in North America,” said Huffman. “The spa took twenty-three months to build and opened in February, 2001. Since then it has exceeded our expectations by delivering a level of tranquility and restoration our guests truly appreciate.”


The majority of the spa is subterranean and the bottom two floors had to be carved out of the mountain using dynamite so as not to obstruct the view from the Inn. It’s situated below the main inn and measures 43,000 sq ft. At a cost of nearly $50 million, there are few spas that can even come remotely close to its size and magnificence. There are two tunnels leading to the spa, and once inside it’s a labyrinth of pools, whirlpools, indoor treatment rooms, couples’ rooms, and an assortment of specialty areas, including 20 water features, seven fire pits, and 16,000 sq ft of amenity areas.

McCracken & Lopez, P.A., headquartered in Charlotte, NC, were the consulting engineers chosen for the spa project. They really had their work cut out for them not only because it was one of the largest spa centers in the world, but it also included unusual aesthetic consideration not typically found on projects of this type.

“The design of the spa was such that it was one of the largest aquatic facilities in the world and the space was divided into many smaller areas, making it truly unique,” noted Dick McCracken, the chief engineer on the project. “But the architectural requirements meant that we really had our work cut out for us to make it all happen.”

The spa space is divided into a variety of pool areas that include a private male and female cold and hot pools, a men’s and women’s hot pool, a central large pool, and saltwater brine pools. The separate pool areas are connected by open walking areas.

“It’s difficult enough maintaining critical water and air temperatures along with desirable humidity levels when each of the spaces is individually enclosed,” remarked McCracken, “but the complexity of the task is multiplied when all the spaces are open to each other.”

McCracken said the largest challenge was to install the mechanical system were it could not be seen nor heard but designed to deliver constant comfort conditions without fail.


The solution McCracken & Lopez came up with was to locate the mechanical room directly below the spa, acting as a sub-basement. While this required extensive construction, the result was direct access to the individual pool areas for the space conditioning air with no ducting visible to the patrons.

It was also decided that separate dehumidification units would be needed to maintain the unique temperature and relative humidity conditions in each spa section. McCracken, working in conjunction with Richard Archer, account manager for Trane Commercial Systems of North Carolina, decided on PoolPak dehumidification systems for the project.

As a representative for PoolPak products for many years, Archer has had plenty of experience with indoor pool installations and knows not all dehumidification equipment is up to the task.

“Most dehumidification units generally work well for a few years after installation but begin having problems because of the corrosive chloramine environment,” said Archer. “We’ve found the PoolPak units have few problems in this area because of how they are built.” Archer also commented that Grove Park Inn required that the Spa run 24/7, with virtually no interruption in comfort.

A total of six PoolPak dehumidifiers were installed having a combined moisture removal capacity of 382 lb/hr with each unit ranging in capacity of 11 to 90 lb/hr. The combination of PoolPak SWHR and AWV models allowed flexible capacity to maintain the many pools and waterfalls within the area. Multiple units also made it possible for scheduled downtime of individual units without interruption to the space conditions.

The four dual-fan SR units control the main body of the spa while the PoolComPak AWV units manage the men’s/women’s hot tub and cold plunge areas. Humidity levels are kept on the lower side, between 50 and 55% rh, while the water temperatures range from 84° in the lap pool to 103° for the hot tub, down to 65° for the cold plunge pools.

McCracken said despite the enormity and complexity of the installation, the commissioning went well with few problems. The PoolPak units operated as designed and continue to operate efficiently with few interruptions and down time. But McCracken is still awed by the magnitude of the project.

“When you consider the size of the spa with all its open spaces, pools and waterfalls, along with the temperature and humidity variations throughout the space, it truly is a project worthy of the Grove Park name.”ES