Moderna opts for smart prefab (re)skylight from Hak4t group

A prefab skylight in which artificial light, daylight, solar shading, sustainable energy and ventilation are integrally controlled in one go. That is the product the Hak4t Group from Dedemsvaart is working on. A first version was installed at Moderna in Hardenberg, where the 14 prefab elements were installed on the roof in just 50 minutes.

Marc Hakvoort of the Hak4t Group from Dedemsvaart wants to lift the skylight to a higher level and is working on a "smart prefab (renovation) skylight," which combines several functions. That smart product will be prefabricated modularly in the factory and then put on the roof in one operation. Prefabrication of skylights of this size is not exactly common, but it provides enormous benefits, Marc Hakvoort has experienced.

Fast construction process

"We delivered fourteen prefab smart skylights of about 5 x 2.20 meters to Moderna Textielservice in Hardenberg. We make these prefab elements at the working width of the roof sheets. So you can simply close the roof and place a prefab skylight in place of one or more roofing sheets. You simply shoot or bolt these on. The total lifting and installation time together came out to only about 50 minutes."

"But the benefit to the construction process is even greater. The roof is completely closed right away, which means that less rainwater enters the building and it is fall-proof. Normally, after the roof panels have been installed, the roofer has to come first and only then are the skylights installed. Until that time, the nets have to stay in place. Those nets cost money, but also hinder the further construction process inside. Now they can be removed very quickly, so that, for example, the sprinkler installer can get to work right away."

Integral product

Prefabrication thus actually pays off for every skylight, according to Hakvoort, and also helps solve the shortage of construction hands. But prefabrication is not the only thing Hakvoort is striving for in improving the skylight product. "We want to move toward an integral lighting solution, combining daylight, artificial light, shading, ventilation and even energy in one modular product. In doing so, we choose a well-insulated cantilevered curb, so that no steel support profiles are needed underneath for additional stiffening. We make the curb in two parts, so that you can easily replace the plastic skylight itself at the end of its service life, while the basic roof curb remains in place. According to the state of the art, you can then refurbish or renew the old one, so you are working in a circular way."

Intelligent light control

The prefabricated skylights at Moderna are the first examples of such an approach. "Only there we have not yet integrated the artificial light into the skylight. At Moderna's request, we mounted the artificial light in a separate square around the skylights, as we had done before. After all, this concerned an extension and Moderna wanted the same image as in the hall from 2014. However, the artificial light is optimally integrated with the daylight. To this end, each luminaire has its own intelligent control, so that it is always maximally tuned to the amount of daylight. That not only gives a very even light experience, but also saves energy compared to a centrally controlled system."

Ventilation System

The precast elements at Moderna are equipped with a thoughtful ventilation system and have a high insulation value. "Skylights are thermal holes in the roof after all. Therefore, they are increasingly omitted in large industrial buildings. But you still need daylight. We looked at how to combine a good insulation value with ventilation. To do this, the prefab smart skylight consists of a double construction, with a bottom shell and a top shell. The two are balanced with each other and can therefore be opened simultaneously with little force. In doing so, the lower shell moves downward, the upper one upward. The ventilation rate is much higher than with a normal ventilation hatch. When closed, the double shell provides a high insulation value."

"We can also make one of the shells slightly heavier, depending on the requirements. At Moderna, the hatches have to close in case of fire. If you make the top one slightly heavier than the bottom one, it will close automatically in case of power failure. If you want to use them for smoke heat extraction, on the other hand, you make the lower shell heavier."

If desired, the prefabricated smart skylight can also be combined with sun protection, in the form of fixed slats on the outside. Their position is adjusted in advance to the incidence of sunlight. 

Reflective coating

To integrate lighting into the prefabricated smart (remodeling) skylight, Hakvoort applies artificial light under parts of the lower shell. These fixtures are of course equipped with daylight sensors so that the amount of light on the shop floor always remains the same. In addition, Hakvoort uses transparent plastic elements with a reflective coating in the skylight at this location. "That reflective coating is meant as sun protection. But we turn the sheet around and use it to reflect the artificial light we hang under it. This gives you not only direct light, but also indirect light. That's important for the lighting experience."

Preferably, Hakvoort would then also like to elaborate on the energy theme in the skylights. "We can install transparent PV panels on the ventilating upper shell, but we are also working on PV on the shading slats."

Thus, the "prefab (paint) skylight" can become as smart as the customer wants it to be, but it can also be reduced to an almost standard skylight with mainly the advantages of prefab in the construction process. "We offer the smart (paint) skylight both as a modular product and as a custom-made product."