After being criticized for environmental pollution, a crematorium in the small Swedish port city of Halmstad has found a novel solution to its problem. Instead of letting all the heat from the crematorium furnaces escape into the chimneys and then also having to spend energy to cool down the smoke before letting it loose into the atmosphere, the crematorium will now recapture that heat and use it to heat local buildings.
"Instead of all that heat just going up into the air, we could make use of it somehow," said Lennart Andersson, the local cemetery director in Halmstad. "It was just rising into the skies for nothing."
The crematorium plans to begin by heating its own premises, using the superheated water used to cool down the smoke. If there is enough leftover heat, the crematorium plans to connect to the district heating network and heat surrounding buildings.
This is not a new idea. This plan is already in use in several other towns in Sweden and Denmark. The Aalborg crematorium in Denmark has been sending its extra heat to local energy companies since April 2010. A planned new crematorium in Zealand will generate enough energy to heat 100 homes for a year.
The cremation heating plan will save money on more than the crematorium's heating bill. Crematoriums have to spend a great deal of energy and water to cool down the smoke generated by their furnaces. After the water has absorbed the heat from the crematorium's smoke, it is discharged.
Under the new plan, the crematorium will still have to cool down the smoke with water before releasing it into the air. However, now that superheated water will be saved, to be sent into the local heating distribution system to heat local homes.
By law, all crematoriums have to cool the smoke form their furnaces from nearly 2,000 degrees down to 300 degrees Fahrenheit before releasing it. Without cooling, the smoke would carry heavy metals and other toxic materials from the human body into the atmosphere.
A Danish Ethics Council has determined that making use of crematorium heat could not be considered indecent treatment of a human body. Swedish regulations are similar to Danish ones, so no one anticipates any ethical problems. The citizens of Halmstad also approve of the plan. "It's the most sensible way to get rid of the excess heat," said Ernst Jensen, an engineer with the Association of Danish Crematoriums.
Sweden has long been on the cutting edge of finding and redirecting eco-friendly sources of heat. In 2008, another Swedish firm found a way to channel living body heat from the quarter million commuters who pass through Stockholm's central train station to help heat a nearby office building. Instead of being piped out of the station, the excess body heat beyond what is needed to heat the station is being used to heat piped water. "This feels good," said Karl Sundholm, project leader at Jernhusen. "The ventilator aggregates are already there, and even some of the pipes. All we need to do is complement with a few pumps and pipes."