A typical saying is that passive house walls with cellular glass are becoming too thick due to the moderate thermal conductivity. Like most sayings, the truth is something else, it is founded on conservatism. Indeed, Denmark has its first cellular glass passive house and the next one is underway.
The house is a Clean Tech Block result, which is already mentioned in previous blog. Clean Tech Block is a project from Gråsten Teglværk, the University of Aalborg and the University of Ljubljana.
The project is described in a newspaper, the “Der Nordschleswiger”. It is real example of durable building and all the typical certificates are granted.
The choice for cellular glass is obvious:
- air tight (passive house standard)
- vapour tight and so no risk for humidity accumulation
- free from rodents, ants and other animals.
- long if not eternal lifetime
- ecologic, according to the Swiss even the most ecologic thermal insulation
- self-supporting, no deformation due to mechanical load or temperature
- almost the same thermal expansions as the other minerals used in the building
- not expensive if produced by direct foaming of recycled glass.
In our opinion, this is a major step in cellular glass building.
Polystyrene is used in the thermal insualtion world in two versions: XPS (Extruded polystyrene) and EPS (expanded polystyrene). Both are used as thermal insulation in buildings besides cellular glass.
Ants are insects which lives in large groups and may destroy some building materials. It has been found in an extensive work of the Norwegian Institute of Public Health that ants are excaviating XPS and EPS in an important way, while leaving cellular glass in peace.
Hereunder, we give a comparison figure, extended with glass wool and mineral wool.
It is clear that cellular glass is not of interest for ants, which is a major advantage of cellular glass compared to the other thermal insulations. Some people should argue that a laboratory experiment is not the real case. The following XPS-boards, found on a jobsite in Germany in real life says everything.
The damage to the building is clear but these ants do not absorb this polystyrene. It ends as plastic contamination in the soil and is dangerous for the human health. It is amazing that this material is still allowed.