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Keep warm - but save energy
In a time when everyone’s attention focuses on the notion of global warming, CISS contributes to a piece of news of international significance: Companies, shopping centres, airports and other large public and private buildings will soon be able to save between 60 and 80 percent on their electricity consumption used on parts of the operation of pumps in the mixing valves of the air conditioning system. This is the result of the industrial collaboration project that CISS, the Danish Technological Institute, Grundfos and Exhausto have been working on for the past two years. ”Yes, we are talking about a huge reduction here. We have tried doing operation-theoretical tests in a cafeteria, and here, the electricity consumption for the pump operation was reduced from 843 kWh anually to 251 kWh,” project manager Peter Svendsen, the Centre for Energy Efficiency and Ventilation, the Technological Institute, explains enthusiastically. The system upon which the project results were transferred was a state-of-the-art system. If the pumps had not jjust been replaced, the system would have been using around 1,250 kWh annually – whereupon the reduction would have been even more significant. Dreamed of a reduction of 30 percent The result far surpasses the expectations the participants in the project had from its beginning. Back then, vice director of CISS at the time, professor Jakob Stoustrup, expected a reduction in electricity consumption of 30 percent. Project Manager Finn Nielsen from Exhausto’s Development Department explained at the beginning of the project how they intended to achieve this reduction. ”Exhausto manufactures heating and air-conditioning systems. Usually, when we sell a heat recovery system with a water heater, it gets connected through a valve. In this project, we replace that valve with a Grundfos pump which can be capacity-controlled to not perform to a larger degree than what is strictly necessary. If the project has a succesfull outcome, we will be able to develop an entirely new electricity-conserving system based upon that technology.” During the duration of the project, a test facility consisting of, among other things, a heating and air-conditioning system from Exhausto and a pump from Grundfos been situated at the Danish Technological Institute, and at Aalborg University, PhD student Mohammad Komareji, CISS, has been working on programming the test facility to make it achieve the largest possible reduction. Hopefully ready to go into production soon Chief ingeneer at Grundfos, Niels Bidstrup, earlier explained one of the challenges that the project was facing: ”There are a lot of ingrained prejudices concerning these types of applications in our world – for instance that you have to avoid using speed-controllable pumps in parts of the heating and ventilation system by all means; you should rather strive towards achieving a constant flow. We need to determine whether there is any truth in this – or whether they are really just prejudices. Once this is settled, we need to find out how to use the speed-controllable pumps to achieve the largest possible number of kilowatt hours a year.” Today, this all belongs to the past. Now, project manager Peter Svendsen looks forward to the final meeting of the project group. This will take place in August 2008. ”But we are already so far into the development of a prototype that in principle, Exhausto could be ready with the first electricity-reducing system at the end of 2008. It may be slightly more expensive than the current systems, but it will soon recover its expenses. And even in existing systems, it will be worth the while to change the control strategy,” Peter Svendsen emphasises. |
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