Waste heat is a fantastic source of energy to replace the use of primary fuels to raise the temperature of processes or building spaces. However all too often these sources can be ‘islanded’ i.e. the producer cannot utilise all the heat and/or it is too remote from consumers for them to use. Longer term storage or the use of heat networks can help overcome these problems and avoid heat being rejected into the environment.
When it comes to sources of heat, a project delivered for a local council brought us into contact with a waste heat recovery opportunity in a particularly sensitive context. Crematoria operate several important processes, one of which is the removal of mercury from the combustion chamber flue gases. This process requires that the gases be cooled to a certain level to avoid damage to the flue gas treatment processes, this heat is available at a temperature suitable for direct use in building heating systems. The engineering is relatively simple; working sensitivity in an environment where families are saying their final goodbyes is less so.
In the case of Skipton Crematorium, the system had been designed by the manufacturer to include atmospheric heat rejection via a dry air cooler, but also provide a heat exchanger for heat recover that had never been utilised. Instead, heating and hot water for the working and ceremony areas were provided via a large domestic scale gas boiler and radiators.
Being that most construction and installation information was no longer available, detailed site survey visits were required to assess both the existing heating system and the locations and functionality of the heat exchange equipment. In a working crematorium this meant carefully co-ordinated, and time limited, visits outside of workings times were required. Additionally, site photographs had to be carefully arranged, so as not to show detail of any out of bounds areas dictated by the facility staff. Accessibility was also restricted due to the installation of modern crematory systems in an 1870’s listed building.
Ultimately, we determined that the output from the existing plate heat exchanger, through liaison with equipment suppliers, had 3.5 times the capacity of the existing gas boiler. We recognised that not only was it possible to supply the main chapel, but with suitable pipework, an additional building on the site could also be heated.