Finally an ideal temperature and ample clean air

New climate systems for penguin enclosure at Blijdorp Zoo

Penguins are very sensitive to temperature and humidity. If the conditions are out of their ideal range for a prolonged period, they can develop respiratory infections, often caused by fungal infection. To prevent such infections as well as ensure a healthy and comfortable environment for the feathered animals, Blijdorp Zoo replaced the climate control system in its penguin enclosure. To do so, the Rotterdam zoo joined forces with specialized partners Flow Care Installatietechniek, Plan2Be, Jabrulier and Western Airconditioning. The goal? An ideal temperature and plenty of clean air.

Blijdorp Zoo is the only zoo in the Netherlands to house king penguins. The Oceanium currently houses a colony of 25 adult king penguins and five chicks. In addition, the penguin enclosure houses a large number of gentoo penguins. The maximum temperature for a penguin enclosure is 12°C with a relative humidity around 40%. To make this possible, the penguin enclosure at Blijdorp Zoo was recently equipped with a new air handling unit, chiller and measurement and control installation. 

Restore Quality

In the old situation, the penguin enclosure was equipped with an air handling system with only a coarse air filter and two chillers. "The installations dated from 2000 and had reached the end of their technical lifespan," says Randolph Streng, Technology Advisor and Manager of Building Management Oceanium at Blijdorp Zoo. "As a result of the salty climate, several plant components had corroded, making their operation unreliable. In the hot summer months, the desired (cold) temperature of a maximum of 12°C was no longer achieved. In addition, the air filtration was inadequate. As a result, not only the quality of the enclosure deteriorated, but also the health and well-being of our penguins." 

"Penguins have a body temperature between 37 and 39°C," Streng says. "Both king penguins and gentoo penguins are very sensitive to fungi such as Aspergillus fumigatus, which do not occur in their natural habitat in the Antarctic. The fungus particularly thrives at temperatures above 12°C. Therefore, it is important to keep the penguin enclosure ónder this temperature. But also to properly filter the air so that the dust that attracts the fungi is effectively captured. We asked our regular installation partner Flow Care Installatietechniek to design a new installation for this, which meets the latest technology and achieves the temperatures our animal caretakers want." An important wish was also to link - in line with Blijdorp Zoo's sustainability ambition - the new installation to the 2021 Oceanium's heat and cold storage (WKO) system. "Thanks to this connection, not only does the indoor climate for the penguins improve, but it also enables the simulation of our seasons."

Technical development team

Flow Care Installatietechniek has been regularly carrying out projects for Blijdorp Zoo for 20 years, with climate systems that are proven to work and meet the exotic specifications of the Rotterdam Zoo. "For the climate control of the penguin enclosure in particular, sufficient air movement, good air purification and better control of the temperature were essential," stresses Ewald Baars, director/owner of Flow Care Installatietechniek. "To meet these requirements as well as to determine the right project specifications, I involved Richard Beeloo, director of consulting firm Plan2Be. Together we set up a technical development team with Melanie Bloem and Nedim Mehmedbegovic, who are both associated with Blijdorp Zoo as technical consultants and are very familiar with the requirements for the construction and air-conditioning of animal enclosures. Together with Melanie and Nedim, we translated the wishes and requirements of Blijdorp Zoo and its animal keepers into a technical starting point document. In addition, we carefully mapped out the structural condition of the penguin enclosure. For example, where could the new air handling unit and chiller best be located? And what did this mean for plant engineering? How could we interface with the CHP system? Based on this, Richard calculated the required air volumes and cooling capacities and the technical design was further developed and discussed over a year."  

Regulation and monitoring

In the preparatory phase, the necessary systems and suppliers were also identified, Baars says. "With some regularity, we then ended up with Jabrulier and Western Air Conditioning, who shared their extensive knowledge and expertise and guided the implementation of their products in the technical design. In addition, we actively collaborated with B&S Measurement and Control Technology to control the components. The new climate system of the penguin enclosure is linked via BACnet to the Oceanium's SAUTER building and automation system, allowing the new air handling unit, the new chiller, the release of valves and the running of pumps to be very precisely controlled and monitored."

Corrosion-resistant air handling unit

"Following the cooling load calculations and air flow rate calculations, air circulation in the penguin enclosure had to be considered at an early stage," says Ivo Hovius, owner and sales manager at Jabrulier. "The enclosure has a salty climate, so at least the inside of the air handling unit had to be made corrosion resistant. For example, to protect all components that come into contact with recirculation air. As an organization, we have extensive experience in the construction of stainless steel 316 air handling units, which are frequently used in the offshore industry. Based on this experience, we recommended that not only the internal plating, but also as many components as possible be constructed in stainless steel 316." In addition, to ensure the reliability of the air handling unit, robust built-in components were chosen. Also with regard to the cooling coil, which has received a seawater-resistant coating. "The cooling coil also has a wide fin spacing of 6 mm, because very deep cooling is done with ice water. Combined with extensive detection measures, this minimizes the risk of frost formation on the cooling coil."   

Three-stage air filtration

A key wish of Blijdorp Zoo and Flow Care Installatietechniek was to efficiently filter viruses and fungi in the penguin enclosure. "In order to blow the conditioned air in as cleanly as possible, we investigated various filter combinations," said Hovius. "Based on this, we chose a three-stage air filtration system that perfectly meets the fresh air needs of the penguins. Both the return air and freshly drawn outdoor air are first filtered through an F7 air filter, which, in addition to coarse dust, also protects against fine dust and pollen. Then the air passes an F9 air filter for the filtration of fine and ultrafine dust with low air resistance. As a final step - for the cooling coil - a HEPA H14 filtration is performed for extreme protection against pollen, viruses and mold."      

Free cooling

The air handling unit can move an air volume of 10,500 m3/h, with a maximum outside air share of 5,000 m3/h, Hovius emphasizes. "This allows - when the outside air temperature allows - 'free' cooling for part of the year." The minimum setting is 2,500 m3/h. "The air handling unit is divided into a return air, outside air and exhaust air section, using the same size and type of fan for each section. Thanks to the use of EC fans, energy-efficient operation is ensured." Because Diergaarde Blijdorp has taken a number of spare fans into stock, parts can be exchanged easily and quickly in the event of an unexpected failure. 

The air handling unit is installed indoors, in a fairly warm room and under a flat roof. To install it, part of the facade had to be dismantled. "Special transport was also needed to bring the three parts inside," Baars says. "Because of the hot space, extra attention was paid to the insulation of the air handling unit." Hovius: "Our WK-com THERMO offers the highest attainable thermal insulation class (T1) and thermal bridge class (TB1). Thanks to additional insulation at the bottom and corners, condensation is also avoided at all times."

New chiller

To ensure that the penguin enclosure stays at temperature 24/7, sufficient cold air supply is essential. "The air handling unit therefore contains two cooling batteries," Baars explains. "The first battery is connected to the WKO installation, which provides basic cooling. If more cooling is required, Western Air Conditioning's chiller jumps in. This chiller is connected to the second cooling battery and positioned on the roof of the Oceanium."

"With our chiller, we make cold water at -5°C," says François van Gorkom, account manager at Western Air Conditioning. "This can cool the air in the air handling unit from 12 to 4°C. At part load, we can go even colder, down to an air inlet temperature of -3°C." The cooling capacity of the new chiller at this water stage is 42 kW.

Low GWP, high seasonal efficiency

"A chiller with R-32 refrigerant (GWP = 675) was chosen especially for the penguin enclosure," Van Gorkom says. "In order to control the chiller precisely, we used an inverter compressor that is demand-controlled up and down from 100 to 10%. This ensures a high seasonal efficiency of 4.7, which also meets the sustainability ambition in this project. Compared to a chiller with R-410A refrigerant, the seasonal efficiency is as much as >25% higher! The low-noise chiller is also internally extra acoustically insulated and operates whisper quietly."

Silent transition

The replacement of the climate system was completed last summer. "We first built the new installation, then last June we switched from the old to the new situation in one day," Baars says. "This transition was completely silent. The penguins didn't notice anything, except that their stay has become much more pleasant." Stern: "The new installation has now been in use for several months and we clearly notice a difference. Our penguins are doing very well. Recently 5 chicks were even born! Also, the penguins are enjoying the mountain of ice that is replenished daily in the enclosure much longer. It now remains visible and is not melted within an hour. It is also very nice that we save a lot of energy in the new situation. But also that our quarantine area can now be used effectively."

Preventing infections

The penguin enclosure houses a nursery, care kitchen and quarantine area for new or sick penguins in addition to the general living area with basin and rockeries. "With the arrival of the new air handling unit, we can now also run quarantine," Streng says. "Indeed, thanks to a separate duct, separate control and separate exhaust fan, the air extracted from the quarantine area is not reintroduced into the enclosure but is effectively exhausted outside. This prevents contamination from the quarantine area."

Pleasant cooperation

A few months after completion, Streng, Baars, Beeloo, Hovius and Van Gorkom look back on a beautiful and successful project, in which cooperation and thinking together were very pleasant. "Together we realized a terribly beautiful and fun project, with an installation that is unique in its application," concludes Streng. "Everyone's input and advice was listened to very carefully. This is how we arrived together at the best solution for Blijdorp Zoo and its penguins."