Rising energy costs, clean-air legislation, dwindling resources – there are many compelling reasons for industry to get its energy efficiency act together, and just as many ways of going about it. One area that offers enormous scope for energy and cost savings is filtration and air handling (ventilation and air conditioning) technology. Consequently, it’s an area that features very strongly in the new Environmental Technologies and Resource Efficiency display at HANNOVER MESSE.
Air handling systems: it pays to use the right filters
The amount of energy consumed by air handling systems is relatively high. In Europe, for instance, the fans used in these kinds of systems account for somewhere between 10 and 20 percent of the industrial sector’s entire electricity consumption. In office buildings, air handling fans account for a good 40 percent of total consumption, while in cleanrooms the figure is closer to 80 percent. The point here is that roughly a third of this energy is used to overcome the flow resistance – or pressure loss – caused by air filters.
One very effective way of reducing energy consumption in air handling systems is to use high-efficiency frequency-controlled fan motors. Unfortunately, retrofitting these sorts of fans to existing systems can be a fairy time-consuming and expensive exercise. A relatively simple and effective alternative, therefore, is to use energy-efficient air filters. Filters that meet EUROVENT Energy Efficiency Class A standards, for example, can deliver annual energy cost savings of up to 24 percent.
Two in one: air cleaning and heat recovery
Even greater savings can be achieved by recovering heat from process air. The German clean air specialist Keller Lufttechnik GmbH calculates that waste heat recovery can reduce the energy required by a process-air handling unit with a design flow rate of 10,000 m3 by more than 70 percent.
Production hall air-cleaning systems of the kind used, say, in the metal industry offer considerable scope for the recovery of waste process heat. While conventional systems extract warm process air, filter it and vent it unused to the outside, the latest generation of air cleaning systems have integrated recirculation technology that enables the cleaned process air to be re-used inside the production hall. In some cases this technology can even eliminate the expense and inefficiency of running a make-up air unit to bring in and heat up fresh air from the outside. In many cases, these advanced heat-recovery air-cleaning systems can be implemented as stand-alone units – no need for pipes and ducts. They can be used in this form in production halls where high smoke and emission levels are an issue, such as MAG welding workshops in the steel fabrication sector. They capture the warm, smoke-contaminated process air via intake ports, filter it and then feed it back into the hall via jet diffusers. In turn, the air circulation created by this process pushes the contaminated air towards the intake ports. And, of course, the air inside the hall is kept at a constant, even temperature.
The growing market for air handling technology
The enormous energy savings made possible by advanced air-handling and filtration technology translate into strong market growth in Germany and Europe-wide. A study conducted by the University of Trier on behalf of the German Air Handling Unit Manufacturers’ Association (Herstellerverband Raumlufttechnische Geräte e. V.) indicates that in Germany, central air handling systems recovered some 20.1 terawatt hours (TWh) of heat in 2013. The study anticipates this figure will increase to around 33.2 TWh annually by 2020.
Discover these and many other high-efficiency, cost-saving solutions at the Energy 2015 trade fair at HANNOVER MESSE.