Specifications

23
FINALIZING SYSTEM DESIGN
At the core of every successful natatorium design is
a system that provides the operator the year round
conditions they expected while meeting ASHRAE design
standards, satisfying local codes and being as energy
efficient as possible.
This design guide has covered many important aspects
to consider and putting it all together properly can
become a daunting task. The Seresco team has worked
on thousands of indoor pools and developed a helpful
checklist to help ensure all vital aspects are considered
during the design process. Seresco understands also
that product flexibility is essential to allow the designer
to work around all the project-specific issues while not
compromising their design, and offers the most flexible
product line in the industry. The overall performance of
a Natatorium will be directly impacted by the number of
deviations and compromises taken in its design.
Once all the design parameters have been established,
the only remaining decisions will be: what would they
like incorporated into their Seresco dehumidifier and
what they want provided externally. Unit mounted
heating coils, exhaust fans, heat recovery packages,
weatherproof outdoor cabinets and heat rejection to
cooling towers/dry-coolers/outdoor condensers are
some of the configurations available from Seresco.
The project specific details generally dictate what is the
most appropriate.
Key Design Concerns
for Traditional* Pools
The back cover of this manual is a handy checklist that
covers the Key Design Considerations. Soft copies of
this checklist are also available from our website at:
SerescoDehumidifiers.com/DesignGuide.
* Please contact factory for Waterparks and pools
heavy with water features. Design standards have been
established for ‘traditional’ bodies of water and do not
adequately address the special needs of these facilities.
Step 1: Operating Conditions
Do not guess. Get the desired pool water temperature,
room temperature and relative humidity in writing from
the owner.
Operating conditions have a tremendous impact on
the entire design and cannot be changed by a large
degree after the fact. It is critical that the designer
educate the customer on the implications of their
operating temperature choices. Maintaining the room air
temperature 2°F-4°F above the pool water temperature
will help reduce evaporation – but the temperature must
still be comfortable to the patrons. Reduced evaporation
in turn reduces the pool water heating requirement.
Step 2: Supply Air
Calculate the supply air requirement of the space
based on the room volume. Your target air change rate
per ASHRAE is 4-6 volumetric air changes per hour,
with a 6-8 air change rate in spectator areas. This is a
calculation and sets up the entire air handling systems.
• Supply air must get down into the Breathing Zone.
It is critical for comfort and good IAQ that the treated
supply air get down to the pool deck and occupants.
• If using fabric duct all the same air distribution
and duct design rules apply. You must ensure
supply air gets to where it is needed or IAQ
problems will result.
• Ensure the return duct location compliments the
supply air duct location and promotes a good air
pattern. In a large natatorium, several return air grilles
might be required to achieve a good air pattern is
the space.
• Be careful to avoid air short circuiting or placing
supply diffusers too close to the return duct opening.
This can ruin the effectiveness of the supply air and
give any return duct mounted sensors false readings.
Step 3: Outdoor Ventilation
Per Local Codes
Most localities have adopted Standard 62 as their local
code. The baseline outdoor ventilation air requirement is:
• 0.48 CFM/ft² of water surface area and deck for
regular pool.
• If you have a spectators seating area, add 7.5 CFM
per spectator during swim meets.
Introducing more outdoor air than codes is not
recommended. In winter it will increase space heating
and pool water heating costs significantly. Too much
outdoor air in winter can also lower the relative humidity
levels to uncomfortable levels for the patrons.
• Outdoor air must be filtered.
• Ensure the airflow is balanced when the system
is commissioned.
Finalizing System Design