Gwynne Anthony 2020

ART506 Dissertation 2019. Anthony Gwynne . 43 Insulation product U-value no worse than 0.21 U-value no worse than 0.3 Minimum thickness (mm) Minimum thickness (mm) Non vapour permeable insulations Polyisocyanate insulation board (PIR), for example: Kingspan Kooltherm K18 Insulated Plasterboard or similar with a Lambda value 2 of 0.020 W/(m 2 k) 92.5mm fixed over battens 62.5mm fixed over battens Notes: 1. Solid stone wall 500mm thick. 2. The lambda value, also portrayed as ‘K-value’ or ‘λ- value’, measures a product’s thermal conductivity in units of W/(m 2 k). A good insulation will have as low a lambda value as possible to reduce heat loss (www.kingspan.com) . Figure 15: Comparison of non vapour permeable insulation thicknesses fixed to internal face of solid walls 1 for U-values no worse than 0.21 and 0.3 W/m²k in compliance with figure 14 (Source: Ty-Mawr). Insulation product U-value no worse than 0.21 U-value no worse than 0.3 Minimum thickness (mm) Minimum thickness (mm) Vapour permeable insulations Cork board Lambda value 0.40 W/(m 2 k) 180mm applied directly 120mm applied directly Lamb’s wool Lambda value 2 0.038 W/(m 2 k) 220mm between studs 140mm between studs Wood fiber board Lambda value 2 0.040 W/(m 2 k 180mm applied directly 120mm applied directly Notes: 1. Solid stone wall 500mm thick. 2. The lambda value, also portrayed as ‘K-value’ or ‘λ- value’, measures a product’s thermal conductivity in units of W/(m 2 k). A good insulation will have as low a lambda value as possible to reduce heat loss (www.kingspan.com) . Figure 16: Comparison of vapour permeable insulation thicknesses fixed to internal face of solid walls 1 for U-values no worse than 0.21 and 0.3 W/m²k in compliance with figure 14 (Source: Ty-Mawr). Figures 15 and 16 demonstrates non vapour permeable insulations such as Polyisocynate (PIR) are more high performance and thinner in profile when compared to poor performing non vapour permeable insulations such as cork, lamb’s wool and wood fiber. This makes PIR type boards more attractive when upgrading traditional solid walled buildings but is totally inappropriate.