Shopping Air

Most shopping centres are located in urban environments and are therefore exposed to significant particulate matter pollution due to the high traffic volume.

Air pollution places enormous demands on filter systems.
Nowhere are the measured values for particulate matter higher than in city centres, such as in Stuttgart, the capital of the southern German state of Baden-Württemberg. In Stuttgart's case, this air pollution can be attributed to the city's topography. Stuttgart is situated in a basin and protected by the Black Forest and several other low mountain ranges; this results in fairly low wind velocities in the basin. It also means, however, that the wind doesn't just blow away the dust like it does in other cities. On up to 89 days per year, a particulate matter concentration of more than 50 micrograms per cubic metre of air is measured. On 35 days, this concentration violates EU laws.

It should come as no surprise that shopping centres, such as the Gerber building in Stuttgart, require particularly efficient filter systems to keep the hazardous fine dust away from building occupants and visitors. The issue of particulate matter is also finding its way into international standards. While filter classification to EN 779 was based on a particle size of 0.4 μm in the past, filter efficiency is now tested using three different particle sizes ranging from 0.3 to 10 μm. This is an important step towards avoiding particulate matter pollution.

TROX has developed effective and efficient filter systems to handle the high levels of particulate matter found in city centres.

Shopping centres are among the more wasteful consumers of energy. Their energy requirements – electricity, heating and cooling – account for an increasingly large portion of operating costs. This demand can mainly be attributed to conventional lighting systems and their high cooling loads (up to 200 W/m2), which need to be dissipated by ventilation and air conditioning systems. In light of the growing number of shopping centres and their considerable energy requirement, developing sustainable ventilation and air conditioning schemes for this type of building is an absolute necessity.

This is the subject of a joint research project of TROX with the E.ON Energy Research Center of RWTH Aachen University and the IEK of Leibniz University in Hannover, Germany.

The supply air requirement of a retail location is often the result of cooling loads, rather than the fresh air flow rate necessary for hygiene-related reasons. For this purpose, the air quality in shops with specific goods was tested, namely goods that emit a certain odour, such as shoes, books or clothing; the air quality tests were based on how test persons rated it on a reference scale (acetone percentage in the air). It has then been determined that the air change rates could be reduced by up to 50% without any negative effect on the shopping centre air quality or comfort level. The thermal load can then be dissipated by energyefficient air-water systems, for example.

Demand-based volume flow control.
The occupancy of shops varies greatly and continuously. This is why demand-based control of ventilation and air conditioning is necessary for energy-efficient operation. The VOC level, measured with a sensor, indicates whether many or few people are present in a room; if only few people are present, a certain portion of air can be recirculated into the ventilation system. As more people enter the room, the portion of recirculated air is reduced, and the portion of fresh air is increased. With heating mode during the night, the supply air is 100% recirculated air.

Further energy savings potential is opened up by aerodynamically optimised diffusers, energy-efficient air-water systems that dissipate high heat loads, and heat recovery systems that make use of the energy of waste air.

Energy-efficient fans.
Fans move air from one location to another. To do so, they need energy. That's why fans, just like all other energy-consuming products, are subject to the so-called 'ecodesign directive' for energy-related products (ErP). The objective of the ErP Directive 2009/125/EC is to lower the energy requirement of products such as fans by an environmentally friendly design. X-FANS products are tested on a certified test rig (to the ISO 5801 test standard) to ensure their energy-efficient operation.

Shopping malls are complex buildings. They require the highest levels of safety and comfort, both of which can only be guaranteed by perfectly integrated systems and components.

The TROX system 

Specialist consultants think in terms of integrated systems. They don't want to deal with interface issues between technical building services. Hence the market demand for comprehensive solutions in the field of indoor air conditioning and, specifically, for the systems that control them. To meet this demand, TROX has developed subsystems where an air handling unit acts as the centre of the automation network.

The X-CUBE air handling unit acts as the centre of the automation network and controls and monitors all ventilation and air conditioning components: volume flow controllers are controlled via Modbus, for example, while fire dampers, smoke control dampers and process air fans are controlled using the proven AS-i system.

The table on the fold-out page provides an overview of the most relevant air onditioning parameters to consider for the different areas of a shopping centre.