Article from Installation & Construction with our General Manager Wilfried van Mierlo.
Building on Curaçao differs in many ways from building in the Netherlands. This is apparent, for example, during the new construction of the Hospital Nobo Otrobanda in Willemstad. Not only the tropical climate, but also the logistical possibilities have a major influence on the building materials to be used, construction method and installation technology in the general hospital. These are the words of Arjan Pleysier, senior advisor at Deerns and Wilfried van Mierlo, general manager of Valstar Simonis BV, who are involved in the project as building physics and fire safety advisors and installation advisors respectively.
Deerns and Valstar Simonis BV are part of the consortium that is carrying out the Design, Build and Maintain project under the leadership of main contractor Ballast Nedam. “We are confronted with the necessary challenges in this,” begins Pleysier. “For example, the heart of the building is formed by a large, non-air-conditioned atrium, around which various heavily air-conditioned departments are set up.” To prevent internal condensation due to vapor transport from the outside to the inside, Deerns recommended vapor-tight materials for the outer walls of the ORs – where a temperature of 18°C is required.
east wind
Although the atrium is not cooled, the temperature here may not rise slightly higher than the outside temperature. “The design is geared to this,” says Pleysier. Curaçao has to deal with easterly winds more than ninety percent of the time. By directing that wind through the atrium via glass slats, a pleasant indoor climate is achieved, while heating by the sun is prevented.” In principle, these slats are open day and night, he says, but they can be closed in extreme weather. “The consequence of the fixed external sun protection in the other rooms is that not only less sunlight, but also less daylight enters the building. As a result, we have not achieved the points for a LEED Gold delivery certificate in this area. But this is more than compensated for in other areas, for example in the area of acoustics.”
Limited cooling capacity
Induction units cool all air-conditioned rooms down to a maximum of 23˚C, says Van Mierlo. “Special sluices at negative pressure ensure that the warm, moist air from the atrium cannot penetrate to the wards.” In order to remove all construction moisture and – in case of calamities – moisture from the air, all induction units are equipped with a condensate drain.”
The air treatment installation in the hospital is set up in such a way that the cooling capacity remains limited, despite the strict indoor climate requirement, he explains. “In total, we install about 25 air handling units of various sizes in and on the various wings of the hospital. A double set of heat wheels per cabinet ensures that the air-conditioning is very energetic. The extracted, relatively cool and dry air is used to pre-treat the fresh outside air.”
In addition to the climate installations, Valstar Simonis BV has provided advice on the electrical installations, fire alarm system, nurse call systems and emergency power installation in the building. During the implementation, the company mainly has a controlling function. The same goes for Deerns.
'Chilled water air treatment installation keeps Hospital Nobo Otrobanda at the right temperature'
The construction of the new Hospital Nobo Otrobanda on Curaçao is in full swing. With the state-of-the-art hospital, the government wants to raise healthcare on the island to a higher level. The design therefore harks back in all its facets to the history, culture, climate, environment and population of Curaçao.
WG Trapenberg Air-conditioning Service NV is commissioned by the main contractor Ballast Nedam to engineer, assemble and construct the chilled water installation and climate control system for the hospital, including the chilled water pipe network and air ductwork. The company also takes care of the installation of the necessary air handling units, cooling machines, chilled beams, grilles, and so on. “The installation provides air treatment (cooling) for all patient rooms, operating rooms, visiting rooms and the hospital's reception area,” says director Willem Trapenberg. “Very strict requirements were therefore imposed on the installation and the materials used. The LEED Gold certification criteria formed the basis of the design.”
In total, a number of chilled water fresh air air handling units will be installed on the roof of the new hospital, he says, which will control the ventilation systems in the various rooms, as well as the chilled beams. “Cooled beams are used in some of the rooms, while small air handling units have been chosen in other rooms. By using water as an energy carrier instead of refrigerants, we make an important contribution to the environment and safety in the building, as all refrigerant is kept outside the building.”
The new building of the Hospital Nobo Otrobanda is the largest project in the history of WG Trapenberg Air-conditioning Service NV.
