ASHRAE Journal - April 2015 - 43

2015 ASHRAE TECHNOLOGY AWARD CASE STUDIES

Photo Credit: SeaWorld

ABOVE Ride load and initial scene.
LEFT Liquid desiccant units dehumidify the

ride areas.

The design team was tasked with several engineering
challenges to make the exhibit ideal for the animals and
enjoyable for the guests:
* Maintain animal health through temperature, air
quality, filtration, and pressure relationships;
* Moisture control;
* Odor control; and
* Energy efficiency.

Animal Health
Animal comfort and health were the main key performance indicators for the design of the HVAC systems
with indoor air quality being the most critical. Penguins
are susceptible to aspergillus and other molds and fungi
that are common in our environment but not theirs. The
design uses high level filtration, airflow patterns, and
space pressure relationship to keep the bird's environment healthy.
There are only a few exhibits in the world that allow
the face-to-face interaction that was incorporated
into this exhibit. Guests are first washed by clean air
as they enter the facility. Specific fresh air exchange
rates are maintained for the animal areas. All fresh
air delivered to the exhibit (either directly or through
any possible infiltration) is HEPA filtered. HEPA level
filtration along with a non-homogeneous electrical field system are provided in rooftop air handling
units that recirculate the air in the space. In addition, there are specific space pressurization measures
that control where air is allowed to enter the animal
spaces.

Moisture Control
The HVAC cooling coils required to maintain the
spaces below freezing temperatures, used a 15°F cooling fluid. Constructing a proper envelope around these

spaces minimized the infiltration of potential moisture
into these cold spaces.
* Due to the large temperature and humidity level
differences across the envelope, the vapor drive is
significant. Creating a tight sealed barrier around the
low-temperature exhibit was imperative.
* Guest entry and exit points had to be controlled.
Sally port vestibules with special door controls were
incorporated into the design to allow guests to easily and
comfortably enter the exhibit while revolving doors at
the exit protect the underwater viewing area.
* Fresh air supply is pre-conditioned by an active
desiccant system. This very dry fresh air helps to lower
the humidity levels in the exhibit space.
Envelope. Early in design, a good envelope was identified as an important requirement to minimize the
sensible and latent loads and to curtail potential issues
with condensate. Detailing to minimize even the smallest potential leak through this envelope is critical. If
moisture is allowed into the wall system, ice will form,
causing damage. Where ice doesn't form, condensation
will form, and, over time, likely cause mold and mildew
growth.
The design team recommended the insulation/
vapor barrier envelope be built outside of the building structural frame of the cold penguin exhibits,
to provide a cocooning envelope surrounding the
cold space and eliminate the majority of the thermal
bridge issues. Where thermal bridges could not be
eliminated (as with the acrylic viewing panels and the
mechanical space where the HVAC units are located),
the dew-point temperature on the warm side had to
be controlled so that condition condensation cannot
form.
Sally Ports. The design team worked with the storytellers and show designers to ensure the integrity
APRI L 2015

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