State-of-the-art wood stoves could be an attractive solution for the space heating of passive houses. The question of the integration of wood stoves in passive envelopes is rather new and still open, the main constraints being the power oversizing ant the heat distribution. The paper proposes a low-resolution simulation approach to provide an insight into the whole-year thermal comfort using a stove, and into the relative effect of the large number of physical parameters involved in the problem. In particular, a simple stove model is developed for detailed dynamic simulations in order to fairly represent the heat emission properties of small airtight stoves. As an example, the methodology is finally applied to a test case, here a typical detached passive house.
It is becoming conventional approach to evaluate the building envelop losses using detailed dynamic tools such as EnergyPlus, ESP-r and TRNSYS. However, the user-related loads (and their variations) in the building are usually oversimplified during performance evaluation of those buildings and associated HV AC systems. This paper presents a methodology to evaluate the performance of buildings and their energy supply systems while taking into account the user-related loads (non-HV AC & DHW) at individual household levels. For this purpose, a single family house (two different insulation cases) built in Oslo climate using an alternate duty air to water heat pump is used as a case study. The investigation shows that a large variation occurs in space heating needs for the same standard house when actual user loads are considered. The study also shows that the storage losses dominate the performance of total heat supply system in case of passive house insulation.
Realisation of Net Zero Energy Buildings (NZEB) for residential use depends on, among many other things, minimizing air leakages. However, very airtight houses will have an increased risk for problems regarding indoor humidity, thermal comfort and indoor air quality. Focusing on ventilation systems becomes a requirement in this situation. For cold climates, mechanical ventilation systems are the state of the art solution and in order to achieve a further reduction in energy use, the focus must be on efficient energy recovery. This paper focuses on a quasi-counter flow membrane-based heat and moisture recovery system for cold climates such as the Norwegian climate. The membrane separates the two air streams and allows both heat and moisture transfer. Its effectiveness is crucially depending on the heat and mass transfer resistance of the membrane that separates the two air streams and therefore the characteristics of membranes have to be deeply analysed. To analyse the membrane, this study starts with a detailed theoretical study of the forces governing transfer through membranes. A literature review of available measurements for membrane resistance is performed. Following this, heat and mass transfer in selected types of membranes will be measured in order to validate the results of the theoretical analyse. The conclusion to be taken from this study is the selection of the characteristics of the most suitable membrane for a residential heat and moisture exchanger in cold climates.