Statement on the VDPM and VdL study on “energy-saving paints”
Von ThermIQ
Summary
ThermIQ is a functional facade coating. Its benefit rests on solar reflectance, moisture protection, vapour permeability and protection of the building fabric — not on the thermal resistance of an insulation material. ThermIQ claims no thermal conductivity (λ value) and is not offered as a substitute for thermal insulation or an external thermal insulation composite system (ETICS). The study published by VDPM and VdL tests the thermal resistance of a thin layer as if it were an insulation material. ThermIQ does not claim this property — and the chosen method can neither capture nor assess the actual mechanisms of reflective functional coatings.
1. Background
The German association for insulation systems, render and mortar (VDPM) and the German paint and printing ink association (VdL) have warned against "insulating paints" and "energy-saving coatings" in a position paper and published the results of a study by the Institute of Building Physics at Leibniz University Hannover. The position paper is available at wirsindfarbe.de (the full test report is available from VDPM).
ThermIQ welcomes the scientific scrutiny of building products. Advertising with physically implausible values — such as thermal conductivities close to that of a vacuum — is dubious and harms the entire market. On this point we expressly share the associations' criticism.
A sound assessment, however, requires that the test method matches the product's working principle. That is not the case here.
2. What ThermIQ is — and what it is not
ThermIQ is a reflective, vapour-permeable and water-repellent protective coating for facades, roofs and industrial plants. It works through building-physics surface effects, not through the thermal resistance of a thin layer:
- Solar reflectance: High reflectance reduces solar heat gain into the building element. This lowers surface temperatures and the cooling load in summer and relieves the building fabric.
- Moisture protection and vapour permeability: Low water absorption keeps the wall dry while water vapour can escape to the outside. A dry wall keeps its building-physics properties; moisture-related deterioration of the thermal conductivity of building materials (design values per DIN 4108-4) is avoided.
- Protection of the fabric: Protection against UV, algae, mould and micro-cracking extends the life of facade and roof.
ThermIQ does not replace thermal insulation and claims no λ value. We do not claim to make an ETICS superfluous. Our coating is meant to complement existing systems — it also protects already insulated facades against solar heating, moisture and algae. In particular, we promise no heating-energy savings from an "insulating effect" of the paint layer.
3. Why the study does not assess ThermIQ
From a building-physics perspective, the methodological limits of the study are clear:
a) The relevant standard procedures were not applied
The properties relevant to functional coatings — solar reflectance, water absorption, water vapour permeability — are determined by their own recognised standard procedures. These were not used in the study.
b) The test systematically excludes the core principle
The test took place at constant outdoor temperatures in a climate chamber, i.e. without solar radiation. The central mechanism of a reflective coating — reducing solar heat gain — cannot, in principle, appear when every radiation source is excluded. Nor does the set-up capture the moisture behaviour of real building elements. That no difference to a neutral paint arises under these conditions is therefore not a statement about the product's effect but a consequence of the test design.
c) It tested an insulation effect that is not claimed
The test measured the electrical energy needed to maintain a constant indoor temperature — a classic insulation test to determine thermal resistance. That a 0.5 mm coating has no significant thermal resistance is undisputed and matches our own statements. ThermIQ does not claim this property.
d) The U-value describes only part of the thermal behaviour
The U-value covers only steady-state heat transfer by conduction. The thermal behaviour of real buildings is also shaped by solar radiation, long-wave thermal radiation, surface properties, moisture and dynamic temperature profiles. Basing an energy assessment on thermal conductivity alone ignores these factors.
e) One product, a name in common, a verdict on a whole category
A single product was tested: "BAUTER Nano-Dämmung" by BAUTER Deutschland GmbH, based in Berlin, advertised with a thermal conductivity of 0.0000877 W/(m·K). Because of the shared name we want to be clear: BAUTER GmbH in Vienna, which sells B-ThermIQ under the ThermIQ brand, has no connection with that company. Both were, in the past, general agencies of the same manufacturing group. ThermIQ advertises neither this nor any other λ value; a value of this order of magnitude is not physically plausible.
From this single test specimen, a sweeping verdict is drawn about a technically heterogeneous product category. Reflective functional coatings differ considerably in formulation, working principle and properties; generalising from one specimen to all products of this kind is not tenable.
f) On the interests involved
The study was commissioned and published by associations representing manufacturers and distributors of insulation systems, renders, mortars and paints — suppliers whose products partly compete with functional coatings. That is legitimate and does not make the results wrong per se. It is, however, appropriate to read a category-wide negative verdict based on a single specimen chosen by these associations with due caution and to complement it with independent tests.
4. Where we agree with the associations
We expressly agree that "miracle paints" advertised with implausible λ values harm the market, that thermal properties must be proven by suitable, standards-compliant methods and accredited bodies, and that consumers are entitled to verifiable information. That is precisely why ThermIQ documents its properties through independent tests, including by TÜV NORD.
5. Verified properties of ThermIQ
| Property | Value | Reference |
|---|---|---|
| Total solar reflectance (TSR) | 93 % | measured per ASTM C1549 |
| Solar absorptance αS | 0.07 | derived from TSR (αS = 1 − reflectance) |
| Reduction of solar heat load | by calculation | calculation standard EN ISO 52016-1 |
| Water absorption | class W3 (lowest) | EN 1062-3 |
| Vapour permeability (sd) | 0.16–0.17 m (vapour-permeable) | EN ISO 7783 |
| Thermal emissivity ε | ≥ 0.85 | ASTM C1371 |
| Fire classification | B-s1,d0 (flame-retardant) | EN 13501-1 |
| Moisture-dependent thermal conductivity (design) | – | DIN 4108-4 |
We provide all test reports and data sheets on request.
6. Conclusion
Innovations must be tested — that is right. But test methods must fit the product. A coating that works through solar reflectance, moisture behaviour and surface temperature cannot be assessed with an insulation test based on λ or U-values. The overall energy performance of a building results from several measures working together and cannot be reduced to a single parameter or product category. Insulation and functional surface coatings do not pursue identical but complementary goals.
ThermIQ therefore calls for a differentiated view that clearly distinguishes between classic insulation materials and functional surface systems with other working principles. We support transparent, standards-compliant testing and are available for professional dialogue with associations, test institutes and energy consultants.
Contact: ThermIQ – Thermal Building Protection · +43 664 456 6724 · anfragen@thermiq.at · thermiq.at
This statement may be quoted in full and without changes.