Q2. What is the purpose of this study?
The purpose of this study is the use of Phase Change Materials (PCM) for the renovation of light weight buildings like tertiary buildings.
Q3. How much energy is stored in new buildings?
New buildings represent about 1% per year of the total amount of buildings, which means that the key to decrease rapidly CO2 emissions is renovated buildings.
Q4. How much energy is consumed by buildings?
Housing and tertiary buildings are responsible for the consumption of approximatively 46% of all energies and approximatively 19% of the total CO2 emissions [2].
Q5. What is the effect of the surface cooling on the globe temperature?
The air temperature and the radiant temperature have an effect on the globe temperature by the mean of convective and radiative heat transfer respectively.
Q6. What is the main disadvantage of light weight buildings?
Sensible heat storage has been used for centuries by builders to store/release passively thermal energy, but a much larger volume of material is required to store the same amount of energy in comparison to latent heat storage.
Q7. How many times more energy is stored in a building?
Considering a temperature variation between 18◦C and 26◦C, variation that is very common in low inertia building, the PCM stores about 3 times more energy than water and 6 times more energy than concrete (figure 3) for the same wall thickness.
Q8. What is the main purpose of the paper?
Most of the studies in the literature deals with either numerical modeling (for example [7])or laboratory experiments (for example [8]) in order to effectively asses the use of PCM in walls.
Q9. How many sensors are installed in the ceiling?
Each wall and the ceiling are equipped with 4 temperature sensors (Pt 1000 sensors with an accuracy of ±0.6◦C) located at the different layers interfaces.
Q10. What is the temperature of the composite PCM?
The air temperatures, the surface temperatures and internal walls temperatures are measured using PT1000 sensors with an accuracy of ±0.6◦C.
Q11. What is the time to analyze the improvement of the thermal comfort of a renovated building?
Of course, this improvementcan only be efficient if the building before renovation is of low inertia and if the temperature variations are around the phase change temperature of the PCM.
Q12. What is the analysis of the results for the period between February and December 2007?
The analyze deals with the globe temperature to take into account the air temperature and the thermal comfort enhancement due to the walls surface temperature.
Q13. What is the thickness of the PCM?
The thickness of the PCM is the result of a commercial compromise and allows77% of optimal efficiency obtained with 1cm thickness [9].
Q14. What is the composition of the composite PCM?
The product tested, ENERGAINr has been achieved by the Dupont de Nemours Society and is constituted of 60% of microencapsulated paraffin within a copolymer.
Q15. Why is the composite PCM enthalpy important?
This particularity is due to the possibility to incorporate much more PCM in the polymeric material than in a traditional construction material, for example:⋆ 26wt% of fatty acids PCM in gypsum - see [11],⋆ 35wt% of paraffin in gypsum - see [12],⋆ 5.6wt% of butyl sterate PCM in concrete block; 8.6wt% of paraffine inconcrete block - see [13].