Reducing energy consumption
The price of energy has appreciably increased in recent years, and will probably continue to rise in the coming years. The owner of an old house need not, however, settle for large energy bills because the energy consumption of the house can be reduced to a low-energy level during renovation.
Solutions that cut energy consumption are based on reducing heat losses from the envelope and ventilation of the building, as well as on the efficient utilisation of free energy.
Heat losses can be reduced:
1. By improving the capacity and functionality of the thermal insulation of the envelope.
2. By improving the airtightness of the envelope.
3. By improving the heat insulation and tightness of windows and doors.
4. By using controlled ventilation in the building.
5. By recovering the heat from exhaust air from the ventilation system.
Improving the heat insulation capacity of the envelope means either using more efficient thermal insulation with thicker structural layers or materials with better insulating capacity. Also, any possible heat bridges are replaced with better structural solutions. The critical parts of the windows and doors are usually the joints of the pane and the wall structure. By improving the tightness of these seams, the overall thermal insulation capacity of the structure is improved. The thermal insulation capacity of the glass parts of the window can be improved with, for instance, additional glazing, coatings or sealed glazing elements.
From the viewpoint of energy economy, procedures that improve a building’s airtightness and controlled ventilation are most profitable when planned and implemented simultaneously. Also the maximum profit ratio for the heat recovery system for the exhaust air from the ventilation system depends on an airtight envelope and controlled ventilation.