wood fiber insulation materials
Insulating materials based on natural materials have many advantages.
Wood insulating materials or other insulating materials based on natural fibers such as wood wool, wood fiber insulating boards, flax, cellulose and other bio-based insulating materials are now competing with insulating materials based on plastics such as EPS, XPS, PUR and mineral-based insulating materials such as mineral wool or rock wool .
insulation and climate protection
Insulation regardless of the climate?
“Insulation” is a magic word for climate protection today. In most cases, however, these are insulating materials that have not internalized external climate and environmental costs (e.g. the ecological rucksack of the material, recycling options, etc.). One of these inexpensive insulating materials is EPS foamed polystyrene ("Styrofoam").
Wood fiber insulating materials require significantly less energy in production (9 MJ/kg) than mineral wool insulating materials (27 MJ/kg) or plastic insulating materials (77 MJ/kg) with a comparable insulating effect (FWI, 2012). The thicker the insulating material required to comply with the EnEV, the more energy is required in production. Wood fiber insulation boards cause CO2 emissions during production of approx. 50 kg CO2-eq/m³ insulation material, mineral wool insulation materials between 100 - 200 kg CO2-eq/m³ and plastic insulation materials between 50 and 200 kg CO2-eq/m³.
But that's not all, because in principle, with wood fiber insulating materials, the paths in the material flows of the upstream chains can be shortened to such an extent as with only a few other groups of insulating materials, especially not with plastic insulating materials.
The origin and the transport in the upstream chains are important for all groups of insulating materials
As a rule, there is hardly any reliable information available on the transport within the processing chain of insulating materials.
In classic life cycle assessments (EPD), product-independent, standard data sets with 50 to 350 km for the upstream chains are usually calculated. Some studies even calculate with only 75-200 km (IBU) to 562 km (Thünen Institute). But even values of 500 to 600 km probably underestimate the real flow of goods, if you only look at the imports of wood fibers and residual wood to Germany.
However, all raw materials for wood fiber insulating materials could in principle be obtained within a short distance, unlike, for example, oil-based plastic insulating materials. A considerable amount of insulating material is also imported to Germany every year, namely 16,620 t wood fiber, 19,000 t glass, 133,693 rock wool insulating materials and 151,271 t polystyrene (2016). Without proof of origin such as HOLZ FROM HIER, products used in construction and interior design can have traveled thousands of kilometers in transport, even though the raw material itself would have to be sourced very regionally.
For comparison, plastic insulating materials and mineral insulating materials Standard data sets from life cycle assessments (EPD) also calculate plastic and mineral insulating materials with standard data sets of 50 to 350 km for the entire upstream chain.
This cannot be realistic simply because of the basic raw materials described in these products. Here, too, the importance of transport for the ecological balance is vastly underestimated. This is to be demonstrated using material flow indicators for plastic insulating materials.
Example basic raw material oil. Germany has 0.1% of the world's crude oil reserves and the transport of this basic raw material for all plastic products is correspondingly high.
Example of plastic precursors. All preliminary and intermediate products up to plastic granules and above all the plastic granules themselves have material flows worldwide (China has a market share of approx. 50%). For example, annual imports to Germany: 1 million t of styrene polymers, 1.6 million t of propylene and 2.5 million t of ethylene.
However, climate-friendly construction means more than complying with a specific Uw value
If a concrete building is to be as cheap as possible today, plastic insulation is usually attached to the outer wall, often glued. In a solid wooden house, the basic material may (do not have to) be a bit more expensive, but you often need less insulation to achieve the same Uw value. The final costs related to the wall-insulation-façade system are often comparable. The life cycle assessment by no means! In terms of their insulating behavior in the use phase, most modern insulating materials hardly differ today. However, they differ significantly in their upstream chains. Here are three important groups of insulating materials in a brief comparison .
(1) Nawaro insulating materials (cellulose, wood fiber) have a heat storage capacity of 2,000 - 2,100 [J(kg/k)] and a thermal conductivity of 0.04 - 0.045 [W/mK]. (2) Plastic insulating materials (EPS, XPS, PUR) have a heat storage capacity of 1,300 - 1,500 [J(kg/k)] and a Thermal conductivity from 0.035 - 0.05 [W/mK]. (3) Mineral fiber insulating materials such as glass or rock wool have a heat storage capacity of 800 - 900 [J(kg/k)] and a thermal conductivity of 0.035 - 0.05 [W/mK].
Comparison: Price per insulation effect
At first glance, the lower price is the only reason why artificial insulating materials are so much preferred to natural ("Nawaros") today. But a material price per m3 or m2 doesn't really say anything, it depends on the purchased insulating effect. A cost comparison is more correct: Costs per m2 related to the insulation effect with the same insulation factors [W/mk] for all materials. Here it quickly becomes clear: the natural materials also perform well here. at Roof or between-rafter insulation is loose cellulose even cheaper than mineral wool or plastic.
When it comes to facade insulation, wood fiber insulation boards are usually a little more expensive than glass wool or EPS. With a 100 m2 facade area, these are additional costs of <1,000-3,000 € with insulation costs of approx. €16,000 (glass wool) or €17,000 (EPS) for wood insulation materials. However, this additional price also includes significantly more consumer protection and climate protection. In addition, you get a lower value if you consider the wall-insulation-façade as a unit when planning.
Wood fiber insulating materials can also score points in subsequent use
Renewable raw materials can be recycled very well today and are then available again for energetic or material reuse.
Plastic insulating materials, on the other hand, are almost exclusively used in waste incineration plants today, and mineral insulating materials can generally only be disposed of in landfills.