A Local Heat Exchange Network (LHEN) allows different facilities inside a company to exchange heat or cold using heat pumps. The LHEN has a temperature that is more or less in the middle between the cold and the heat requirements.
LHENs are only interesting if more facilities producing cold or heat are interconnected. If it is an application with just one heat source that heats offices and a closed circuit cooler to avoid overheating during the summer, the LHEN does not bring any cost reduction.
A Shared Heat Exchange Networks (SHEN) allows heat and cold exchange with other companies. This makes it possible to forward extra heat during the winter, or to get extra heat during the winter and the summer. This is some kind of urban heating using low temperature water. It means that each connected facility needs a heat pump to get the water at the needed temperature.
I came to the idea of the LHEN/SHEN concept when thinking at improving the efficiency of a building containing an IT Room and Offices.
It looks like the main problem would be that urban heating work with big temperature difference, like 40°C-80°F between the water coming in and going out. This is done in order to move a lot of energy without moving too much water. This might be the main problem of this solution because heat pumps loose efficiency when the temperature difference increases.
To learn more about the concept and its costs, please check the documents below.
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