It is winter. The nights are cold. The days too. We scurry out of the warm apartment in the morning to be in the warm office as soon as possible. Rarely do we waste a thought on the comforting warmth that lets us survive the cold winters. The fact is that this heat (heating and hot water) costs more than 80 percent of the energy we need for the home. Only 20 percent of the energy flows in the form of electricity into light and household appliances. Nevertheless, when we save electricity, we think of turning off a useless lamp rather than consuming our heating. After all, you cannot run around at home with the ski jacket. Sorry planet.
In order to reduce this large energy item, all modern houses are packed thick. 180mm polystyrene or rock wool slabs are the ingredients for standard facade insulation. At Minergie houses it may also be quiet about 200mm. Where, of course, every window reveal and every roof beam is insulated with dozens of different products, it was not until a few decades ago that you blithely fired your way into the dear big world. Insulation was just as foreign as climate change and so many older buildings are still naked and uninhibited in the landscape. If you want to clothe these old houses with 200mm insulation, the windows become peepholes and the monument is standing with raised index finger in front of the door. Deterring an old timber frame house with facade insulation is often out of the question and so the insulation must be installed indoors. If the rooms are suddenly 400mm smaller, simply because the insulation needs its place, the client has no pleasure.
Reflection instead of absorption
A product that is 75 percent thinner than the conventional insulation and yet performs the same performance would have to mislead architects for many reasons to jump in the air. This is what Marco Polla, a former carpenter who today runs a small family business, thought so. He has been selling a product called “ACTIS “for some years, which is made by a French company. A product that works so differently than the usual insulation materials that it conjures up a confused frowning on the forehead of many experienced abdominal experts.
Normal rock wool, which probably also hides between your roof beams, absorbs the winter cold. This struggles through the material until it flows into the attic at the other end. The thicker the material, the more cold it can absorb and the less it gets into the interior. It works the same way in the summer with the heat. However, ACTIS consists of thin foils coated with aluminum. These do not absorb the cold, but reflect it. As the sound waves are reflected on a noise barrier to the highway, the films reflected the cold waves. Already in this statement the problems of MrPolla begin. Problems that he has been struggling with for over 10 years now.
Because this explanation sounds like a lot of people like mischief. Already at the word “cold waves” goes down many professionals of the store. Are there such waves at all? In fact, one encounters in a corresponding Google search only on weather phenomena. A little more fertile is the Internet search for “heat waves”. You quickly come across the term “heat wave heating”. A heater that works with infrared radiation.Infrared. Also a term under which more people can imagine something. But cold waves?
The long fight for recognition
In order to sell his product, Marco Polla had to rely on a certificate from the SIA , the Swiss engineering and architects association. Each insulation material has a so-called U-value. A number that tells the planner how well a material is isolating. These values are set by EMPA , the Swiss Federal Laboratories for Materials Testing and Research. The SIA takes over the values from the EMPA and then publishes them in their brochures. According to Polla, however, the competent expert did not want to know anything about so-called cold waves. The ACTIS products were approved by the EMPAalso always tested with the usual test method, the so-called hot box method. A method that, according to Polla, did not even consider the reflection of the cold waves. Thus, his product received a value which corresponded to only one third of the value mentioned by Polla. This was just the beginning of a multi-year back-and-forth between Polla and the responsible testing center.
He did not fare any better with his persuasive attempts on the construction front. Many architects put him back after five minutes. In fact, a quick internet search on such reflective slides leads to some forum pages that talk about giddiness and mischief. Reliable information can not be found. Only Pollas Homepage, which seems to be a little out of time, seems reasonably serious.
From space to the modern rescue blanket
To underpin the effectiveness of these slides, Polla gives several examples in the interview. As early as 1928, the steel structures of the first skyscrapers in America on the south side had been protected from the heat with folded and polished aluminum sheets. Later, NASA used such reflective films in the outer skin of their spaceships. Today, the insides of the thermos bottles are made of silver-coated reflective material. Every fridge, every oven is insulated with aluminum foil. “If someone has an accident, at minus 10 degrees in the mountains. Is he still protected with military blankets from freezing? No! These are thin foils coated with aluminum.
In order to receive full recognition also on mainland Europe, ACTISbuild two more test houses through the Fraunhofer Institute in Germany. This report from 2009 is still available online under the name “Potentials and Limitations of Infrared Reflective Insulation Materials”. “The mean heating capacity for maintaining the room temperature of 21 ° C during the study period considered (11.12.2007 to 21.01.2008) is about twice as high in the attic space with the infrared-reflective insulation system as in the mineral wool-insulated roof space,” concludes the report. Polla refers to this report in the interview as manipulated, as in the ACTIS experimental house broke and the measurement arrangement of the instruments was changed.
Other modes of operation and calculation
Another handicap of these ACTIS films is their poor comparability with other insulating materials. Abdominal experts are used to getting twice as high a U-value with a doubly thick layer of insulation. 200mm rockwool insulates twice as well as 100mm rockwool. Very easily. For the slides, however, this bill does not work. Doubling the thickness of the films does not give double the insulation value. The textbooks should already be rewritten in the vocational school, or at least supplemented. In order to be able to calculate the insulation value of its product, Polla therefore gives the so-called R-value and not the usual U-value. It was also a great relief for him, as the EMPAhad agreed to issue him a certificate with the R value.
Even if this value was still one-third too low according to Polla. In the meantime, Polla hopes that his product will receive full recognition at the European level and that the Swiss EMPA would then have to make concessions. Because according to Polla, the expert who had refused him recognition in the relevant commission for years at SWISSPOR works today, The largest representative of the Swiss stone wool and glass industry. This industry is afraid of the reflective films. “That’s always the case,” says Polla. “First, a new product is laughed at. Then you try to talk badly and when you realize that it works, you try to displace the product with wrong measuring methods. In this last phase we are now.