Reduce Heating Energy Demand - Basics
You can do one thing to reduce energy costs: Choose a new supplier or a different type of energy which is cheaper. But you will profit only for a few years form this measure.
Ever thought to reduce the energy demand by a thoughtful optimization of your house or flat? This will reduce future costs and the energy demand. O.k., you are right. You have to invest some money. But this is meant by "thoughtful".
Check the balance between investment and benefit for different measures and different options to find the optimum package!
Energy transportation, not energy losses!
Don't think in terms of "energy losses", this is a misleading approach. At least from the standpoint of physics.
We have to understand the existence of three physical effects to transport energy:
- Heat conductivity of materials:
Molecules are not static, they are always in motion. A higher degree of motion corresponds to higher temperatures. Just solid materials show motion: Molecules are jittering about their central position. And they can transfer energy to their neighbour molecules to excite them. This microscopical motion is, seen from the macroscopical view, heat. Heat flows from warmer (hotter) regions of a body to cooler regions. - Transportation of heat with materials - convection:
Material is heated up by a heat source and the material is transported to a cooler region. There it releases its heat to the cooler environment. Just in that case the heat (from a macroscopical point of view) is microscopical motion. Warmer molecules hit colder molecules and transfer their energy to the colder molecules. - Transportation of heat with electromagnetic radiation:
Electromagnetic radiation can excite the motion of molecules. Let's think about electromagnetic waves as a field of forces which might shake molecules. Heat radiation or so called infrared radiation is felt a warm radiation.
O.k., that was some theoretical information about the three heat transportation mechanisms we can observe in physics. Now we will check some examples of heat transportation in a common house.
Examples of heat transfer in houses
Let's see some examples corresponding to the above listing of the three heat transfer mechanisms:
- Heat conduction by materials:
The walls and roofs of our houses are able to conduct heat. The direction is always given by the temperature difference. Heat flows always from the warmer side to the colder side
During winter times heat flows form the interior to the surroundings. During summer times heat flows form the outside into the house. - Transportation of heat with materials:
Houses equipped with a central heating use water (in some cases air) to distribute the centrally supplied heat in the rooms of the house.
Otherwise the residual air flow between window and window frame transports heat during winter times out of the house. - Radiation transport:
Heater elements emit heat radiation if their temperature is high enough. Therefore they are called radiators. Another well known example is the incandescent bulb: it emits roughly 95 percent of its energy release as heat radiation, just a few percent of the emitted electromagnetic radiation are light and hence visible.
Evaluating a houses energetic quality
The basic approach is: Look at the paths where
- during winter: energy is transported form the inside to the outside and
- during summer: heat (and sunlight) is transported from the outside to the inside
and check it for the three heat transportation mechanisms
- conduction (material transports heat without material transport),
- convection (heated material is transported) and
- radiation (electromagnetic waves transport heat).
in the most prominent parts of a house:
- walls
- windows and doors
- roof
- basement
Single measures to reduce the heat transportation are discussed in specific articles soon!