Akillo!
2024-07-24 15:31:17
- #1
Because this topic will surely still be Googled by many builders here: The transmission heat losses of a building arise from: heat conduction, convection, and radiation losses.
A thermal imaging camera can only meaningfully prove reductions in a building's heating load if the type of insulation reduces all three loss factors linearly according to their shares of the total loss.
With XPS/EPS/compressed fleece/glass wool/hemp/straw/sawdust, this is true cum grano salis. If the new infrared radiation value is measured after insulation, then its reduction corresponds to the total expected reduction of the heating load.
The space industry (from which the nano paint originates) has faced the challenge since the invention of the satellite to master the strongly differing thermal stresses of spacecraft. With a nano coating, i.e., a pure paint, it is easily possible to equalize the thermal conditions of the sun-facing and sun-shielded sides of, for example, the ISS. However, the key point is that in space neither convection nor heat dissipation exist because there is a vacuum. So, figuratively speaking, it can be achieved that no one inside the ISS burns their hand on the sun-facing side nor does anyone freeze their backside by pressing it to the sun-shielded side.
But why do high-temperature-resistant ceramic materials protect the space capsule during re-entry into the Earth's atmosphere? Answer: Not because NASA or Elon Musk are too stupid, but because the nano coating only deflects radiant heat, not convection/heat conduction.
Nano coatings therefore reduce the share of radiation in transmission heat losses. And quite well. An exact value of the infrared share for masonry/wood/plastic/sheets is not found online. The convection share probably strongly depends on wind exposure. The conduction share depends on the moisture content of the outside air. Depending on the weather conditions, one is dealing with a fluctuating share. And precisely then, when the heating load increases due to weather (wind chill/heavy rain), the infrared share decreases.
And this concerns long-wave IFR, whereas the solar irradiation gains consist of short-wave IFR.
The reduced long-wave IFR radiation by a nano coating probably accounts for a low, single-digit percentage of the transmission heat losses and would—even with a "efficiency" in this respect of almost 100%—expressed in a pseudo-lambda value of, e.g., 0.000049—be no real recommendation compared to the obvious costs.
An extremely high insulation exists with high vacuum storage tanks. Their half-life can easily be nine months. They are thus suitable for seasonal storage of sensitive heat. Their construction is also clear: double-walled with the gap filled with an IFR-reflecting granulate.
Analogously, there are vacuum insulation panels, which according to their own statement achieve a lambda of 0.004. Provided that the production of a sufficiently high vacuum in the material is actually achieved process-technically, then such a value would be realistic. However, this is probably not interesting in terms of price. In confined spaces or when a slim aesthetic is desired, it is probably sensible.
A thermal imaging camera can only meaningfully prove reductions in a building's heating load if the type of insulation reduces all three loss factors linearly according to their shares of the total loss.
With XPS/EPS/compressed fleece/glass wool/hemp/straw/sawdust, this is true cum grano salis. If the new infrared radiation value is measured after insulation, then its reduction corresponds to the total expected reduction of the heating load.
The space industry (from which the nano paint originates) has faced the challenge since the invention of the satellite to master the strongly differing thermal stresses of spacecraft. With a nano coating, i.e., a pure paint, it is easily possible to equalize the thermal conditions of the sun-facing and sun-shielded sides of, for example, the ISS. However, the key point is that in space neither convection nor heat dissipation exist because there is a vacuum. So, figuratively speaking, it can be achieved that no one inside the ISS burns their hand on the sun-facing side nor does anyone freeze their backside by pressing it to the sun-shielded side.
But why do high-temperature-resistant ceramic materials protect the space capsule during re-entry into the Earth's atmosphere? Answer: Not because NASA or Elon Musk are too stupid, but because the nano coating only deflects radiant heat, not convection/heat conduction.
Nano coatings therefore reduce the share of radiation in transmission heat losses. And quite well. An exact value of the infrared share for masonry/wood/plastic/sheets is not found online. The convection share probably strongly depends on wind exposure. The conduction share depends on the moisture content of the outside air. Depending on the weather conditions, one is dealing with a fluctuating share. And precisely then, when the heating load increases due to weather (wind chill/heavy rain), the infrared share decreases.
And this concerns long-wave IFR, whereas the solar irradiation gains consist of short-wave IFR.
The reduced long-wave IFR radiation by a nano coating probably accounts for a low, single-digit percentage of the transmission heat losses and would—even with a "efficiency" in this respect of almost 100%—expressed in a pseudo-lambda value of, e.g., 0.000049—be no real recommendation compared to the obvious costs.
An extremely high insulation exists with high vacuum storage tanks. Their half-life can easily be nine months. They are thus suitable for seasonal storage of sensitive heat. Their construction is also clear: double-walled with the gap filled with an IFR-reflecting granulate.
Analogously, there are vacuum insulation panels, which according to their own statement achieve a lambda of 0.004. Provided that the production of a sufficiently high vacuum in the material is actually achieved process-technically, then such a value would be realistic. However, this is probably not interesting in terms of price. In confined spaces or when a slim aesthetic is desired, it is probably sensible.