Phase change materials (PCMs) have opened a new door towards the renewable energy future due to their effective thermal energy storage capabilities. Several products have recently found their way to the market, using various types of PCMs. This paper focuses on one particular wall-board product, integrated in a well-insulated wall constructed of an interior gypsum board, PCM layer, vapor barrier, mineral wool, and a wind barrier. The wall is tested with and without the PCM layer in order to get comparative results. Experiments are conducted in a traditional guarded hot box. The hot box is composed of two full-scale test chambers, where the tested wall is located between those two chambers. There are two heaters inside the metering box: heater 1 functions as a thermostat which is used to maintain a constant air temperature (of about 20 ºC) in the metering box, while heater 2 is a normal electrical heater that provides a constant heating power when turned on. The cold chamber has a fixed temperature equal to –20 ºC. The experiments are arranged in a comparative way, i.e. comparing walls with and without a PCM layer. Temperature, heat flux, air velocity, and electrical power are recorded during testing. By applying well-distributed thermocouples, the influences of the PCM layer on the interior temperatures can be shown. Furthermore, with attached heat flux meters, the energy storage effect and convective heat flows can be determined. Finally, with the electrical power meter, the energy saving effect can also be calculated. In this paper, initial experimental results are presented, showing the indoor air and surface wall temperatures. The experiments show that inclusion of the PCM layer in the wall reduces the interior air and wall temperatures by a maximum of about 2 ºC compared to a wall without PCM. The results also show that increasing the air velocity over the interior surface during the heating period lowers the maximum air and surface temperatures by the end of the heating period.

Abstract

Electrochromic materials (ECM) and windows (ECW) are able to regulate the solar radiation throughput by application of an external electrical voltage. Thus, ECWs may decrease heating, cooling, lighting and electricity loads in buildings by admitting the optimum level of solar energy and daylight at any given time, e.g. cold winter climate versus warm summer climate demands. It is crucial to be able to compare the dynamic solar radiation control for different ECWs and hence require specific ECW properties. The solar radiation control for ECWs may readily be characterized by several solar radiation glazing factors, where a comparison for various ECW configurations enables one to select the most appropriate ones for specific smart window applications in energy-efficient buildings. As an example a particular ECW based on the ECMs polyaniline, prussian blue and tungsten oxide is presented, being able to regulate as much as 60 % of the visible and
59 % of the total solar radiation.

Summary

At the Research Centre on Zero Emission Buildings of NTNU, a new test facility (Living Laboratory) is currently in the final stage of construction and will start its operation in summer 2015. The Living Laboratory was designed to carry out experimental investigations at different levels, ranging from envelope to building equipment components, from ventilation strategies to action research on lifestyles and technologies, where interactions between users and low (zero) energy buildings are studied.
The test facility is a single family house with a gross volume of approximately 500 m3 and a heated surface (floor area) of approximately 100 m2. It is realized with state-of-the-art technologies for energy conservation measurements and renewable energy source exploitation. In this paper, the test facility is described and its architectural features and technological aspects highlighted. The focus is then placed on the detail description of the proposed measurement and control system.