Energy affects temperature
Energy in a building is partly generated from occupants emitting heat and partly by the electrical energy used in the building which is transformed into heat. For example, the energy from lighting, computers, refridgerators and freezers along with solar radiation through windows and on the building walls and roof add energy in the form of heat to a building.
If the temperature outdoors is wamer than indoors, heat will enter by heat conduction through all surfaces of the building. Conversely, if warmer indoors, heat will be conducted through the building envelope to the outside. In addition to conduction, heat is transported through the building envelope by infiltration, i.e. air flow through the building envelope. Large volumes of heat can be transported into or out of the building via ventilation flows.
To control the temperature in buildings there are heating solutions capable of supplying heat in the cold winter months, and also comfort cooling systems designed to transport heat away in warmer periods.
Temperatures in northern Europe
Northern Europe, focus on keeping buildings heated during the cold winter months. Due to the colder climates, heating accounts for a large percentage of the total energy consumption in buildings, and one of the most effective measures for achieving better energy performance is to upgrade the construction of the building. With improved insulation and better window glazing and an airtight building envelope to reduce infiltration, there is less need to supply heat to compensate for the energy leaking from the heated space.
The time it takes for the temperature in a room to change depends on the difference between the energy supplied and the energy extracted. Energy per unit of time is referred to as power, and the greater the net heating power, the faster the temperature rises and vice versa – the greater the net cooling power, the faster the temperature falls. Besides power, temperature change is influenced by the building and the amount of energy it can retain. A heavy concrete building can store a large amount of energy, and thus counteract a temperature change better than a timber building of lower mass. A building’s thermal inertia is important to take into account when designing cooling and heating systems, as this greatly influences the capacity needed.