Fact Check: Applying yoghurt to windows can lower indoor temperatures by up to 3.5°C.

Fact Check: "Applying yoghurt to windows can lower indoor temperatures by up to 3.5°C."

What We Know

The claim that applying yoghurt to windows can lower indoor temperatures by up to 3.5°C has recently gained attention. A report from Yahoo News indicates that an experiment found that indoor temperatures in a house with yoghurt on the windows were, on average, 0.6°C cooler, with a maximum reduction of 3.5°C during hot and sunny conditions. This effect is attributed to yoghurt's ability to form a thin film on the glass, which reflects some incoming solar radiation due to its light color.

Additionally, a proposal by British engineer Tom Greenhill suggests using yoghurt as a low-cost, low-energy solution to keep homes cool during heatwaves (Dezeen). The theoretical basis for this method is that the yoghurt coating can deflect heat, thereby reducing indoor temperatures.

Analysis

While the initial findings from the Yahoo News report are intriguing, they are based on a single experiment that has not been widely replicated or peer-reviewed. The claim of a maximum temperature reduction of 3.5°C is based on specific conditions—namely, "hot and sunny" weather—which may not be applicable in all situations or climates. Furthermore, the average reduction of 0.6°C suggests that the effectiveness of yoghurt as a window coating may vary significantly depending on external conditions.

The sources supporting this claim, such as the experiment mentioned in the Yahoo article, lack detailed methodological transparency, which raises questions about the reliability of the results. The experiment's design, sample size, and control measures are not discussed, making it difficult to assess the validity of the findings.

In contrast, the Retail Food Inspection Guide for Permanent Food Facilities and other food safety sources do not address the application of yoghurt in this context, focusing instead on food safety and inspection practices. This indicates that while the idea may be novel, it is not grounded in established scientific research or practices.

Conclusion

The claim that applying yoghurt to windows can lower indoor temperatures by up to 3.5°C remains Unverified. Although there is some experimental evidence suggesting a potential cooling effect, the lack of rigorous scientific validation and the variability of results under different conditions make it difficult to accept this claim as fact. Further research is needed to confirm these findings and understand the practical implications of using yoghurt as a window coating.

Sources

1. Retail Food Inspection Guide for Permanent Food Facilities
2. FSIS Sampling for Labeling Claims Verification | Food Safety ...
3. CHAPTER 4 - SAMPLING
4. I tried putting yoghurt on my windows to see if it really ...
5. Experiment finds yoghurt can lower house temperature
6. Yoghurt window coating proposed as emergency ...
7. Yoghurt Risk Assessment (ISO 22000, 7.3 - 7.4.4)
8. Descriptive analysis and early-stage consumer acceptance ...