Men kondens på utsiden av glasset er godt tegn for strømregningen.

Statlige Entra fremmer et nytt powerhouse-prosjekt på Brattøra. Noe mindre enn det forrige, men likevel tolv meter høyere enn tillatt i reguleringsbestemmelsene.

Artikkelen er skrevet av Hermann Hansen

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.

Abstract

The study presented in this paper originated from observations made regarding the thermal conditions during winter in highly insulated dwellings with mechanical ventilation with heat recovery (MVHR). Previous observations indicate an oversupply of heat to bedrooms and a successive extensive window ventilation, which leads to an increased space-heating demand.

Detailed simulations were conducted to explain the causes for the observed thermal conditions and to elaborate improved solutions for heating and ventilation during winter. Various MVHR solutions and control strategies, as well as building design solutions, were investigated regarding their impact on the thermal conditions in bedrooms and on the space-heating demand.

The results clearly illustrates that the supply-air temperature and the temperatures in the living room and bathroom have substantial effects on the thermal conditions in the bedrooms. A one-zone MVHR solution, with approximately the same the supply-air temperature to all rooms, has clear limitations regarding the provision of thermal comfort in bedrooms.

The clear potential of a two-zone MVHR solution, where the supply-air temperature to the bedrooms is controlled independently from other rooms, was observed. With a two-zone MVHR solution, the thermal conditions in bedrooms can be improved and the space-heating demand can be reduced.