The Influence of Energy Renovation on the Change of Indoor Temperature and Energy Use

Abstract

The aim of the renovation of apartment buildings is to lower the energy consumption of those buildings, mainly the heating energy consumption. There are few analyses regarding those other energy consumptions which are also related to the primary energy need for calculating the energy efficiency class, including the primary energy need of calculated heating, domestic hot water (DHW), and household electricity. Indoor temperature is directly connected with heating energy consumption, but it is not known yet how much it will change after renovation. One of the research issues relates to the change of electricity and DHW usage after renovation and to the question of whether this change is related to the users’ behavior or to changes to technical solutions. Thirty-five renovated apartment buildings have been analyzed in this study, where the data of indoor temperature, airflow, and energy consumption for DHW with and without circulation and electricity use in apartments and common rooms has been measured. During research, it turned out that the usage of DHW without circulation and the usage of household electricity do not change after renovation. Yet there is a major increase in indoor temperature and DHW energy use in buildings that did not have circulation before the renovation. In addition, a small increase in the use of electricity in common areas was discovered. This study will offer changes in calculations for the energy efficiency number.

Development and Performance Assessment of Prefabricated Insulation Elements for Deep Energy Renovation of Apartment Buildings

“…In comparison of the energy performance on the basis of variation of total delivered energy we can see that differences were relatively small because the energy for space heating was one of the smallest components of total energy use. However, it is important to see that in calculations indoor temperature set point was 21 • C. It was shown by preceding studies [67][68][69] that indoor temperature set point used is higher, typically 22 • C for post-renovation situation. That a 1 • C rise will affect the amount of delivered energy for space heating in average +33%, EPV for +1.2-+1.4% and the global cost for +1.0-+1.3%.…”

The Impact of Air Pressure Conditions on the Performance of Single Room Ventilation Units in Multi-Story Buildings

“…Several studies have shown that room-based ventilation units in Estonian apartment buildings are not ensuring the necessary air change rate [3,7,18]. Mikola et al [3] point out that as these room units generate high sound power level, people switched ventilation units to the 30% of the maximum airflow.…”

“…In Estonia, multi-story apartment buildings constitute about 60% of the whole dwelling stock, and the majority (75%) of the buildings were built primarily in 1961-1990 [1]. Due to the increase in the price of energy, the energy policies of the European Union [2], the age, construction quality, and poor thermal insulation of the buildings, as well as both morally and technically outdated, obsolete heating and ventilation systems, there is an increasing need for retrofitting [3][4][5][6][7]. Part of the building stock built before the 1990s has already been renovated but for many apartment buildings this process is yet to start [6,8].…”

Commissioning of thermal performance of prefabricated timber frame insulation elements for nZEB renovation

“…Comparison of measured real energy use and energy use predicted by calculations have shown that the energy performance gap is larger for more energy efficient buildings [3]. This could be partly caused by user behaviour [4,5].…”