Research in new methods and solutions for use in the design of new low-rise housing in low-energy class 0

To meet the energy needs of the future, the purpose of this project is to contribute to the development of Danish low-energy houses with a good indoor climate by giving architects, engineers and builders access to recommendations and useful tools for the design of these low-energy houses. Demonstration projects have previously shown that low-energy houses can be constructed in many different ways. In this project, 3 focus areas are considered a) optimal window design b) energy storage in electric heating elements at night c) intelligent control in low-energy houses. Results from each area are described below and reported in the uploaded reports.

a) Optimal window sized and locations in low-energy buildings (Vanhoutteghem et al., 2015)
To encourage the development of suitable designs for new low-energy buildings, the design of windows has been analyzed. The results showed that the choice of the size and direction of the window no longer poses a major problem for the heat demand in well-insulated buildings, as long as a low U-value is used for the window. If an even window distribution is used, the windows can be selected based on the room's requirements for daylight and thus there will be considerable architectural freedom to place the windows in the façade if this is combined with a suitable ventilation and sun protection in the critical south-facing rooms. The windows with sun protection coating can be used as an alternative to dynamically controlled sun protection.

b) Possibility to use energy storage in electric heating elements at night for heating and domestic hot water in low-energy buildings (Leth, 2014)
The purpose of this project is to investigate the possibility of using off-peak electricity produced from wind turbines to cover heating heads and domestic hot water in low-energy houses, by storing heat in electric heating elements in the house's concrete floor during the night. The results showed that storage of heat in the concrete floor in the off-peak period between 00:00 and at 00:06 at night was enough to heat the building, as well as cover its need for domestic hot water, without causing the risk of overheating and congestion on the electricity grid. This solution also proved to be cheaper than installing a heat pump in houses that are not connected to the district heating network.

c) Intelligent control in low-energy buildings (Nielsen, 2014)
Today, there are many buildings that have a higher energy consumption than originally anticipated. Intelligent control of building installations has the potential to reduce this energy consumption, and can at the same time contribute to a better indoor climate. In this part of the project, a strategy for intelligent control of the building installations was implemented in a simple simulation tool for calculating energy consumption and thermal indoor climate. The results showed that it was difficult to achieve large energy savings compared to original management strategy, however, a better indoor climate could be achieved. However, greater energy savings can be achieved if the control is adapted to current conditions and user behavior over time.