NBT Retrofit When to consider hygroscopic insulation

Transcription

1 NBT Retrofit When to consider hygroscopic insulation

2 Overview The Drivers Strategy Building Physics NBT specifications

3 Two Drives 2. Legislation 1. Rising energy costs

4 There is a growing understanding that we are not replacing apples with apples when it comes to replacing fossil fuels and reducing CO2 with renewables

5 14000 kwh/ton ton of woodchip (@ 35% moisture) delivers 2,600 kwh / ton kwh/ton 1 ton of oil delivers 12,055 kwh / ton Oil Woodchip

6 Capital and long term costs of renewable energy. New build 19 Flats

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8 Average UK Energy Use

9 Delivering a High Performance Retrofit Building Envelope. Principle Fabric Heat Loss - [U-values ] Detailed Fabric Heat Loss - [Y-values] Heat Loss through air leakage - Air-tightness Moisture Control Health, Fabric durability

10 Delivering a High Performance Retrofit Building Envelope. Principle Fabric Heat Loss - [U-values ] Detailed Fabric Heat Loss - [Y-values] Heat Loss through air leakage - Air-tightness Moisture Control Health, Fabric durability

11 Delivering a High Performance Retrofit Building Envelope. Principle Fabric Heat Loss - [U-values ] Detailed Fabric Heat Loss - [Y-values] Heat Loss through air leakage - Air-tightness Moisture Control Health, Fabric durability

12 y-values Non-repeating linear thermal bridges

13 U-values Vs Y-values

14 Delivering a High Performance Retrofit Building Envelope. Principle Fabric Heat Loss - [U-values ] Detailed Fabric Heat Loss - [Y-values] Heat Loss through air leakage - Air-tightness Moisture Control Health, Fabric durability

15 Air tightness

16 Air tightness

17 Delivering a High Performance Retrofit Building Envelope. Principle Fabric Heat Loss - [U-values ] Detailed Fabric Heat Loss - [Y-values] Heat Loss through air leakage - Air-tightness Moisture Control Health, Fabric durability

18 Moisture Control Moisture movement within a solid wall Transport Moisture mechanisms Source Vapour diffusion Liquid transport Moisture convection (through leaks)

19 Moisture Control Moisture movement within a solid wall Moisture Source Wind driven rain High internal vapour pressure (vapour production, low ventilation..) High external vapour pressure (solar radiation..) Construction moisture

20 Moisture Control Moisture movement within a solid wall Moisture Source

21 Pavatex outperforms any synthetic insulation. No other insulation will breathe, wick moisture and regulate building temperature, both in the summer as well as the winter. Add to this the fact that it is 100% natural and locks up more Carbon than is used to produce or transport it.

22 Moisture Control Comparison between standard EWI refurbishment and NBT Diffutherm Moisture Source Moisture movement within a solid wall

23 Moisture movement within a solid wall Increased Dampness Due to EWI contribution to airtightness and increased vapour resistance of walls (Polystyrene insulation)

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26 External wall insulation checklist Dynamic moisture assessment only in driven rain area 4. [timber frame only] Understand the interfaces and details, cills, reveals, plinth details etc. Dimensionally stable material not subject to thermal expansion. Impact resistance.

27 Moisture Control Comparison between standard IWI Standard Refurbishment: Moisture Source refurbishment and NBT Pavadentro & Pavadry

28 Moisture Control Comparison between standard IWI Standard Refurbishment: Moisture Source refurbishment and NBT Pavadentro & Pavadry Vapour barrier

29 Moisture Control Comparison between standard IWI NBT Pavadentro System: Moisture Source refurbishment and NBT Pavadentro & Pavadry

30 Moisture Control Comparison between standard IWI NBT Pavadentro System: Moisture Source refurbishment and NBT Pavadentro & Pavadry

31 Hygrothermal simulations Glaser M. transport: vapour diffusion M. source: internal vapour pressure WUFI Most transport mechanisms most moisture sources

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34 Internal wall insulation checklist Moisture regulation, not barrier. No gaps between the wall and insulation. Dynamic moisture assessment. Appropriate room ventilation. Understand the interfaces and details, cills, reveals, joist ends etc.

35 Simple Solutions for a Complex Problem