The Swedish company eGain is seeing growing international interest for its innovative approach to heating system management in apartment buildings, offices and hospitals. By marrying very precise weather prognoses with stored data on a building’s particular characteristics, the eGain system is able to cut energy use by up to 15 percent while maintaining or even improving comfort for residents.
“Buildings are slow,” explains eGain founder and CEO Thorbjörn Geiser. “Heating a large building is like steering a supertanker at sea. A change in the position of the rudder takes a long time to change the ship’s course. And it can take days for the interior temperature in a building to catch up with the system setting, because concrete and steel retain heat in certain ways, heat escapes through doors and windows, the sun may be adding warmth one day but not the next, and so on.”
In installing eGain, the company’s technicians first perform a detailed energy analysis for the subject building, including information on structural heat storage, exposure to wind, ratio of living space to outdoor façade, the amount of glass admitting sunlight at different times of day throughout the year, and more. By comparing this analysis with a number of well-studied reference buildings, the engineers develop a comprehensive picture of how the building’s heating system will perform under various weather conditions.
Next, rather than simply measuring the current outdoor temperature with a sensor and adjusting the flow of hot water to radiators accordingly, as with a traditional heating system, eGain places a receiver on the building to continuously monitor weather predictions for coming hours and days. These five-day forecasts include temperature, wind speed and direction, cloud cover, precipitation and solar radiation. The weather prognoses are highly localised, covering cells of just 10 by 10 kilometres. They are fed to the receiver from the Internet via the mobile phone network.
From the prognosis, eGain calculates an “Equivalent Temperature” to replace the outdoor temperature used in traditional systems to determine precisely how much heat needs to be delivered to the building’s radiators. The Equivalent Temperature is fed to the receiver, which validates the prognosis and makes adjustments for any variations that occur for that individual structure. The resulting instructions can be fed to any standard heating system regulator.
The eGain system is naturally most cost-effective in areas where heating costs are a substantial portion of total operating expenses, but Geiser says that the energy savings potential is not limited to buildings in the cold Nordic climate. A study conducted by the company projects clear cost reductions for typical buildings throughout Europe, from the UK, France and Germany to as far south as Hungary.
During 2009 eGain will expand into Poland, Norway and Denmark. “We see eGain as a natural progression in the history of Swedish companies that innovate in select technical fields,” Geiser says. “With today’s focus on energy costs and climate change, the potential for this technology is enormous.”
Article published in May 2009