At the same time, ventilation and air conditioning are important factors for every retailer and operator of shopping centres. As soon as the shop doors are open, the temperature and humidity must be constant. The fresh air infeed must be perfect at all times even if the customer density is high. However, when the shop has closed, it is important to change these optimum conditions as quickly as possible over to an energy-efficient mode of operation. Flow rate control in line with requirements is therefore an absolute must.
The air conditioning can also have an impact on the premises themselves. Large glass fronts not only attract many customers into the shops, they also result in high heating and cooling loads. This is not a problem if the correct technology is selected. High heat recovery is worth its weight in gold in the winter. The use of alternative energy sources, e.g. the waste heat from systems with commercial cooling or the use of district heating, bring significant operating cost savings. However, the cooling capacity is particularly important in retail outlets. Every retail outlet makes targeted use of its lighting to create highlights and viewing directions, thereby generating a heat load which should not be underestimated. During the summer months, cooling in the form of free ventilation is not usually enough. Here, alternative concepts such as adiabatic evaporative cooling or sorption-assisted air conditioning – also known as the principle of "cooling with the sun" – are available.
The optimum system prevents malfunctions, requires little maintenance and offers optimum accessibility to the components. Intelligent maintenance concepts offer additional security against breakdowns.
In the field of trade and commerce, very high quantities of air are moved. Menerga offer systems for this with a capacity of 51,000 m3/h and more - also as a roof-mounted version of course. All systems are equipped with intelligent control and regulation and always automatically select the optimum mode of operation. For you this means that when the shops are closed, the air volume flow is reduced in line with requirements, i.e. lower nominal values, so that the operating costs are drastically reduced. Before the shops are open and/or before the beginning of operations, the system returns the room conditions to the desired values. If the annual heat requirement is higher than the cooling requirement, Resolair systems achieve maximum values of up to 90% with their regenerative heat recovery. In order to satisfy increased cooling requirements in an energy-efficient manner, use is made of our Adsolair systems. The systems work according to the principle of adiabatic evaporative cooling, where the spraying of water into the return air channel can produce a temperature reduction in the supply air of up to 12 K* – without the use of energy for cooling. The sorption-assisted air conditioning works in a similarly intelligent manner. This is performed in the two steps of air dehumidification and air cooling. For the purposes of dehumidification, warm outside air is passed through a water-absorbing brine solution. Subsequently, this dried outside air flows through a double plate heat exchanger with indirect evaporative cooling, in which it is cooled down by 10 to 12 K* to form the supply air. The diluted brine is regenerated through the use of thermal energy. The heat sources used here are solar thermal systems, district heat networks or waste heat. The air dehumidification and regeneration of the brine are performed in separate circuits. This means that the heat can be stored for an almost unlimited time and without losses in a fluid medium and used when the heat supply is not constant.
* at OA = 34° C / 40% r.h.