Analysis of multi-step control strategies for dynamic insulation systems.

• Rule-based controls suitable for dynamic insulation materials are developed. • The controls can save significant energy use for both heating and cooling buildings. • Good correlation is found between heating and cooling degree-days and annual energy savings. Dynamic Insulation Materials (DIMs) present an opportunity to reduce the energy consumption of buildings by allowing heat transfer through the envelope at times when it is beneficial. Studies in the past have investigated a binary R -value control in which the thermal resistance of the wall is either "on" or "off. This study attempts to improve on this control strategy by maximizing the amount of beneficial heat transfer through the envelope using wall surface temperatures, the heating/cooling set-point temperature, and the temperature in the middle of the wall as parameters. It is found that adding a period during which the R -value of the wall can vary continuously within a defined range has the potential to modestly decrease the heating and cooling energy consumption. However, it is found that the most energy savings can be achieved by using a 2-step operation with settings slightly modified from previous studies. For a parametric analysis specific to a residential building in Golden, Colorado, the optimized operation mode produced heating energy savings of 9.3% and cooling energy savings of 21.0% relative to static RSI-3.8 insulation. Moreover, a parametric analysis was conducted to extrapolate the findings to multiple US cities with different climate zones. It is found that the optimized operation mode offers some energy savings for residential buildings in all US climates, though the extent of the savings and the optimized parameters are dependent on climate. Specifically, climates with low cooling degree-days have the potential for a higher reduction of cooling energy up to 35%, while climates with low heating degree-days are found to have the potential for a significant decrease in heating energy of over 80% relative to static insulation. [ABSTRACT FROM AUTHOR]