As can be seen in the matrix, the objectives in winter are to increase heat gain and reduce heat loss. And are also described some general ideas about how to achieve them.
2.1.1Conduction
The main idea of improving the heat storage is the use of the thermal mass. The idea is to have a material which is able to delay the heat transfer some hours. How it has been analyzed in the previous homework the daily variations in Irkutsk can reach more than 20 degrees. This are the better conditions for the thermal mass to work. During the day, the building stores the heat in the warmer hours. And then at night the heat is released, lowering the heating needs and discharging excessive heat.
This kind of technique is useful when it is applied in permanent residences, while for example in weekend residences, can happen that it is not possible to reach a certain comfort level without a proper amount of time. This can result in reaching the desired comfort level when no one is in the house. For this reason, it is necessary to be careful in applying this technique.
About the materials to use, the thermal inertia depends mainly in 3 properties: thermal conductivity, density and specific heat. Is important to consider the thermal mass which in this case is necessary to consider the volume as well.
In the previous chapter it has been explained that the most used material in Irkutsk is wood. Its properties do not look like the most suitable for the application of the technique. Nevertheless, with a good combination of materials, like for example adding an insulator with a high thermal mass, very good results can be reached. Is important as well to take special care of thermal bridges that can spoil the strategy.
The selection of a good insulator as well as the control of thermal bridges also are the suitable strategies for reducing the global coefficient of thermal exchange (H'T).
About the indirect gains from the warm soil as can be seen in the next graph, in Irkutsk due to the soil temperature is difficult to design an effective passive strategy: in colder months the contact with the soil may be positive since temperatures are in any case higher than the outdoor temperature, while in summer ground will drain heat from the building, witch will worsen the already weak non-heating season. The design will exploit ground contact only in colder months as vernacular architecture suggests, but the thermal exchange will be blocked somehow during summer. Probably exploiting ground ventilation will ensure this effect.