Leverkusen, Germany - Some simple figures show the effective nature of heat insulation with polyurethane rigid foam, says PU raw materials supplier Bayer Material Science.
An uninsulated building from 1960 consumes around 3700 litres of heating oil per 100 sq.m of living space and emits some 9100 kg of CO2 a year. But a house insulated in accordance with the new German Energy Saving Ordinance, needs less than 350 litres of heating oil, and its CO2 emissions are only around 800 kg.
BMS points out that a many countries are tightening up regulations on energy saving for buildings as a result of climate change and rising energy costs. The latest EU directive on improving energy efficiency in buildings, specifies that from 2021 onwards new buildings will have to be, "almost zero-energy buildings."
The company says it is currently witnessing a strong rise in demand for rigid polyurethane foam for heat insulation in more and more countries. The background for this is that, even in much thinner layers than are needed for expanded polystyrene and mineral wool - the two other most common insulating materials - this material delivers the required high level of insulation.
"Bayer MaterialScience is responding to the growing demand with customised polyurethane raw materials and systems, optimised process technologies for manufacturing polyurethane insulating materials and, as part of our EcoCommercial Building Program, integrated energy and material concepts for buildings," said Frank Grunert, head of marketing for the EMEA and LATAM regions for polyurethanes at Bayer MaterialScience, in a company statement.
Globally, buildings are responsible for around 30 percent of greenhouse gas emissions and more than 40 percent of energy consumption. Some 70 percent of heating energy is lost through roofs, facades and basements in uninsulated properties, with windows contributing a further 15 percent.
PU insulation achieves a thermal conductivity grade as low as 024 to 026 because its thermal conductivity is much lower than that of conventional insulating materials. In some cases, they can give twice the thermal protection, allowing use of an insulating layer up to 40 percent thinner.
If the external dimensions of a new building are fixed, the available interior space is therefore greater than for insulation using mineral wool or rigid polystyrene foam. To achieve the insulation level of 21-cm-thick polyurethane insulation with a thermal conductivity grade of 026, for example, mineral wool insulation (thermal conductivity grade 040) needs to be 32 cm thick.
For a given masonry thickness and external wall limit, a wall suitably insulated with polyurethane would therefore be 11 cm thinner and the interior space much larger.
"The increase in living space made possible by polyurethane insulation raises real estate values, particularly in large cities with high prices per square metre, thereby directly compensating for the additional expense of improved polyurethane insulation," commented Dr Lutz Brassat, a technical expert on polyurethane raw materials for insulating boards and block foam, in the Bayer statement.
Insulation using rigid PU foam can save over 50 percent of the energy required for an old building, and a low-energy or passive house standard is possible. The "slimline" polyurethane insulation leaves the architectural character of an old building virtually unchanged. For instance, windows insulated with this material continue to offer a high level of light.
New, customised polyisocyanurate (PIR) foam systems from BaySystems offer much improved fire resistance and develop much less smoke gas than established PIR systems. PIR metal-faced sandwich panels can achieve a B-s1, d0 classification, with s1 representing the lowest smoke gas development class. ["d0" means there are no burning droplets of material].
"These panels are thus an alternative to inorganic core materials based on mineral wool that have until now been the preferred materials when the requirements of smoke class s1 needed to be met for construction projects," said Dr Rolf Roers, a specialist in polyurethane metal-faced sandwich panels at Bayer MaterialScience. PIR sandwich panels are used in particular to construct industrial buildings such as warehouses, production halls and cold stores.
See much more at BMS's display in Hall 6, Stand A 75, at the Duesseldorf fairground, 27 Oct - 3 Nov.