Energy efficiency inside out—what impact does energy efficiency have on indoor climate and district heating?

This research study analyses the relationships between energy supply, energy-efficiency measures and indoor environment. Heat load duration profiles were applied for the purpose of analysing the quantitative impact on district heating production of energy-efficiency measures implemented in the multifamily housing stock of three Swedish municipalities. Further information on interconnections between energy efficiency, indoor environment and district heating was provided by qualitative assessments and stakeholder interviews. The intuitive conclusion is that energy savings captured during the winter season are more attractive to energy utilities. This is often, but not always true. The impact from energy savings will differ based on the heat production profile and the ratio between electricity and heat production in combined heat and power plants. Interviews suggest that residents only occasionally are involved, and energy companies are rarely consulted when property owners are implementing energy-efficiency strategies in multifamily residential buildings. This implies inadequate understanding of the implications to indoor environment and district heating production. Improvements in energy efficiency that go beyond cuts in peak load demand generally imply losses in profitability for energy utilities. There is thus little economic incentive for utilities to help their customers to implement energy-efficiency measures. Most often, energy utilities try to provide incentives through the design of heating prices, but pricing models are often complex and can be too difficult for property owners to understand. In order to achieve energy efficiency in a manner which is favourable for several parties, increased cooperation will be necessary.