The campus' original natatorium was built in the late sixties when there was limited knowledge on how to properly maintain a comfortable and cost-effective pool environment. Pat Massa, the now-retired Aquatics Director, said the internal conditions were appalling.
"There was no mechanical dehumidification in place, and space conditions were maintained through direct ventilation and space heating," said Massa. "The chloramine-laden moisture from the continuous pool water evaporation condensed on all cold surfaces eventually causing extensive corrosion to all metal surfaces within the facility."
Massa said widespread repairs were made to the structure and a mechanical dehumidification system was installed. While the dehumidifier did improve the pool environment, it left much to be desired on overall conditions. He especially noted that the new dehumidifier required much attention and it did not make good use of outside air. Quite frequently the large entrance doors had to be opened to ventilate the space, especially after shocking.
NEW FACILITY ON THE HORIZON
When it came time to expand the campus in the late nineties, a new athletic center was in the planning. Massa, who chaired the Strategic Planning Committee, wanted to build the facility to the highest possible standards. He especially wanted the pool area to be easy to maintain and energy efficient, and was very concerned about indoor air quality (IAQ), making it comfortable for both swimmers and visitors alike.
"In the fall of 1999 I requested and was given the opportunity to take sabbatical for an entire semester to evaluate award-winning pool facilities from the east coast to the Mid-West," said Massa. "In all I visited over 50 facilities of all types and sizes and came back with many great ideas on how we should proceed with our new center."
The college president and board wanted to raise the profile of the college with leading-edge facilities like the new athletic center. The goal was to entice students to choose York College as their first selection and not just make it an alternative option. York College, unlike public institutions, has more latitude in selection process and does not require the lowest bids for the building process.
Massa said he wanted a design firm experienced in athletic facilities as the lead on the project. He strongly suggested top-quality equipment including dehumidifiers, filters, and other components be used to avoid the problems experienced with the previous facility.
LOWERING OPERATING COSTS THROUGH OUTSIDE AIR
Dehumidification requires more energy to manage space conditions than traditional commercial cooling alone because of the high latent load created from the relative humidity (RH) in the space. Mechanical refrigeration will accurately control both RH and temperature but at a high cost due to constant compressor operation.
Energy savings can be elusive. Newer, more efficient HVAC components and energy recycling can reduce operating cost, but are limited to the extent they can contribute to economical operation. To create additional energy savings, compressor operation must be reduced and that's where economizing is most useful.
Economizing describes the use of outside air (OA) as an alternative to mechanical refrigeration for dehumidification, cooling and to some degree of heating. OA also provides ventilation necessary to maintain better air quality and is regulated by ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers).
OUTSIDE AIR GOES FULL CIRCLE
Outside air was originally used to manage the excessive evaporation generated from an indoor pool using a system called Heating and Ventilation. During the sixties and seventies, windows and doors were opened and fans were used to draw the air through the space. Energy was inexpensive allowing continuous heating of the circulating air.
As fuel prices began to soar, the amount of outside air used decreased to reduce heating costs. The result was high facility moisture causing excessive corrosive condensate formation, uncomfortable conditions and even health issues.
The corrosive chloramine-laden condensate attacks any and all metal surfaces with which it comes in contact. This was the case at the original York College facility where the excessive moisture destroyed the drop ceiling, which later had to be removed. In addition, the space between the drop ceiling and roof trapped moisture resulting in massive damage to the ducting, structural components and even the roof.
Mechanical refrigeration systems became more affordable and were adapted to pool dehumidification. They were less expensive to operate than heating outside air, but once again ventilation was greatly reduced to minimize operating cost. Consequently, the indoor air quality suffered once again.
To correct the air quality problems of indoor pools, ASHRAE introduced new standards increasing the required amount of outside air per square foot of pool and deck surface. While this improved the air quality, it added additional operating cost to condition this new incoming air.
SELECTING THE RIGHT EQUIPMENT
"The excessive moisture in the natatorium is not only uncomfortable it is also unhealthy," said Massa referring to the original college swimming facility. "The Chlorine used for sanitation made it difficult to breathe for both swimmers and guests alike and caused very annoying eye and respiratory irritation."
Massa's research clearly indicated that outside air was the key component for IAQ and economical operation in an aquatic facility. Massa worked with design engineers and toured several award-winning facilities, in determining the best fit for a pool dehumidification system at York College.
"What I liked about PoolPak units is they take greater advantage of OA not just for ventilation but for dehumidification and cooling as well," Massa remarked.
The chosen dehumidification units were originally designed to use outside air long before it became mandatory because of ASHRAE standards, with a company that used an air "mixing box" allowing full or partial OA use as conditions permit.
Another important feature of the dehumidifiers was their next generation controller. The Virtual-TechT controller data logs over 400 key unit functions for review at any time. It immediately graphs 20 of the most critical operating functions on components like compressors and fans, all accessible via the Internet. This allows HVAC maintenance personnel and the factory to immediately troubleshoot a problem from any remote location, greatly reducing unit downtime. Massa said the Virtual-TechT controller has many built-in control strategies like Smart Economizing, Dewpoint Control and occupied/unoccupied mode to further reduce energy usage.
Multiple bids were requested by the college from various dehumidifier manufacturers, all with similar qualifications. After working with the design engineers, the company determined the pool size required less dehumidification but required a greater volume of air circulation due to the size of the space. The final configuration consisted of two SWHP 190-C series units having a down-sized refrigeration plant with the appropriate CFM for air changes.
"I liked having two systems in operation because it virtually assures no downtime from system failure," said Massa. "We also tied the units to our chilled water condenser eliminating a separate condensing unit."
ECONOMIZING RECEIVES EXCELLENT REPORT CARD
Not all pool dehumidification equipment manufacturers have embraced the greater use of outside air via an economizer claiming it isn't efficient or is not used frequently enough throughout the year to justify its cost.
Using the remote access function of their Virtual-TechT controller, the company has monitored the York College installation and collected empirical data to the opposite.
The economizer is active 30% of the year in cooling and dehumidifying modes, meaning that during 30% of the year compressor energy is being saved. The net annual economizer savings for York College in this example is $9,400 assuming a kWh cost: $0.14.
Fred Klock, Energy and Control Supervisor for Campus at York College, monitors the energy requirements for the entire campus including the aquatic center. He is also a Certified Pool Operator tasked with monitoring the dehumidifier operation and pool conditions.
The college purchases their energy directly from a grid operator, and is occasionally requested to reduce their kWh consumption as energy requirements spike during seasonal periods. In return the college reduces their consumption and also receives a bonus for assisting in the set back.
"Our pool dehumidifiers run very efficiently year-round, and I monitor the status of the pool facility and equipment at least twice daily," said Klock. "The controller is very sophisticated and allows remote monitoring through any computer station. I have access to system conditions and it's very user-friendly." Klock said the system is almost hands-free, bringing fewer problems in the last eight years than the previous dehumidifier caused in one year.
is a PoolPak International Executive, who has spent the past three decades dedicated to helping building owners manage their property and energy costs through ever improving HVAC products. Through PoolPak, Scozzari has championed energy efficient products and innovations to improve their customers' bottom lines while preserving their facility and customer experience.