Motors and Drives
Fig.1. Associated British Ports achieved a three- year payback by saving an average of 16 maintenance hours per month.”
4 Spiralling energy costs and mandatory compliance with energy-efficiency standards are forcing HVAC and environmental engineers to think hard about minimising their carbon footprint and to focus on air quality and its impact on human health, reports Boris Sedacca.
4 Les coûts énergétiques vertigineux et la conformité obligatoire aux normes d’efficacité énergétiques obligent les ingénieurs CVC et environnementaux à réfléchir sérieusement à la réduction de leur empreinte carbone et à se concentrer sur la qualité de l’air et sur son impact sur la santé humaine.
4 Der spiralförmige Anstieg der Energiekosten und die verpflichtende Einhaltung energieeffizienter Standards zwingen HLK- und Umweltingenieure kritisch darüber nachzudenken, ihren CO2-Fußabdruck zu minimieren und einen Schwerpunkt auf Luftqualität und ihrer Auswirkung auf die menschliche Gesundheit zu setzen.
Environmental engineers grasp the energy nettle
period - often less than a year. However, the cost of implementing VSDs on electric motors is perceived as being too high for some SMEs. Convincing end- users to spend money on energy saving equipment during an economic slowdown is difficult. In the UK there is a culture of sweating our
V
manufacturing assets. However, the money saved by not investing in new equipment can soon be offset by rising energy costs. As time passes, inefficient industrial machines consume more energy and begin eating away at profit, argues Steve Brambley, deputy director of Gambica. “Energy cost will by far outstrip the initial
capital cost of machinery. Inefficient machinery reduces profit because 90 per cent of the total lifecycle cost of motors is spent on energy as opposed to 10 per cent on capital cost,” reasons Brambley. “It is often a badge of pride for some
manufacturing directors to show to their board how long they have sweated assets for beyond their depreciation period - to eke out the last ounce of production, at times regardless of whether this proves to be profitable or not.
ariable speed drive (VSD) motor control can reduce the energy bill on mechanical services installations of all kinds by more than their own capital cost in a relatively short
“This applies in particular to heating, ventilation and air conditioning (HVAC) systems, but also to all kinds of markets where pumps and fans are used, whether it is a data centre, a bank, a hospital or a swimming pool. HVAC suppliers can reduce their cost by not having VSD control, but they miss the opportunity to provide an energy benefit to their customers.” Alun James, Industrial VP at Sagentia, a Cambridge-based consulting group listed on the Alternative Investment Market (AIM) in the UK, believes that taking a holistic approach, including advances in sensor technology, provides ultimate smart energy control. Sagentia has developed several technologies, including imaging systems and acoustic signatures, to monitor and control HVAC. “The key is keeping track of multiple sensing
inputs like temperature because there is a lag in the thermal rise of equipment,” according to James. “Although commonplace with domestic central heating systems, simple on-off or so-called ‘bang-bang’ control systems are very inefficient in commercial and industrial environments. There is no intelligence in a bang-bang system: it is purely reactive. Thermal lag causes temperature control systems to oscillate, so there is hysteresis in the system.”
Installing many sensors can become quite expensive when simpler measures are just as
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