The Influence of Moisture Hysteresis on the Thermal Performance of Bio-Based Insulation
(2025) 16th International Conference on Thermal Performance of the Exterior Envelopes of Whole Buildings 2025 In Thermal Performance of the Exterior Envelopes of Whole Buildings- Abstract
Bio-based insulation materials, such as wood fibre, are gaining attention for their low embodied energy, biogenic carbon storage, and potential to leverage moisture-heat interactions to reduce building energy demands. An unexplored phenomenon that might influence their thermal behaviour is moisture sorption hysteresis, where moisture content depends on whether the material is adsorbing or desorbing water vapour, affecting latent heat and thermal conductivity. This study develops and evaluates a method to incorporate moisture hysteresis into commercial hygrothermal software (WUFI 6.5) by manually partitioning insulation layers into separate " desorption states" based on moisture history. Under controlled, steady-state conditions,... (More)
Bio-based insulation materials, such as wood fibre, are gaining attention for their low embodied energy, biogenic carbon storage, and potential to leverage moisture-heat interactions to reduce building energy demands. An unexplored phenomenon that might influence their thermal behaviour is moisture sorption hysteresis, where moisture content depends on whether the material is adsorbing or desorbing water vapour, affecting latent heat and thermal conductivity. This study develops and evaluates a method to incorporate moisture hysteresis into commercial hygrothermal software (WUFI 6.5) by manually partitioning insulation layers into separate " desorption states" based on moisture history. Under controlled, steady-state conditions, modelling hysteresis yielded modest reductions (a few percent) in net heat flux, primarily by delaying evaporation to warmer periods. However, simulations of realistic Nordic wall assemblies with variable day-night conditions showed negligible overall energy performance improvements, as minor gains from moderated daytime thermal loads were largely offset by increased conduction due to higher moisture levels. While confirming the feasibility of modelling hysteresis in standard industry tools, the current approach remains cumbersome, highlighting the need for streamlined or automated methods. Further research is necessary to explore specific design or climatic conditions that may amplify hysteresis effects, refine modelling techniques, and conduct large-scale validation to improve the accuracy of bio-based insulation performance predictions in real buildings.
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- author
- Ranefjard, Oskar LU ; Niklewski, Jonas LU and Rosenkilde, Anders LU
- organization
- publishing date
- 2025
- type
- Chapter in Book/Report/Conference proceeding
- publication status
- published
- subject
- host publication
- Thermal Performance of the Exterior Envelopes of Whole Buildings XVI International Conference
- series title
- Thermal Performance of the Exterior Envelopes of Whole Buildings
- pages
- 12 pages
- publisher
- American Society of Heating Refrigerating and Air-Conditioning Engineers
- conference name
- 16th International Conference on Thermal Performance of the Exterior Envelopes of Whole Buildings 2025
- conference location
- Clearwater, United States
- conference dates
- 2025-12-08 - 2025-12-11
- external identifiers
-
- scopus:105043492393
- ISSN
- 2166-8469
- ISBN
- 9781964173344
- DOI
- 10.63044/b16ran29
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2025 ASHRAE (www.ashrae.org).
- id
- 6387469e-78ae-47e2-b6cc-acdfeef4a04a
- date added to LUP
- 2026-07-17 09:31:12
- date last changed
- 2026-08-11 12:40:41
@inproceedings{6387469e-78ae-47e2-b6cc-acdfeef4a04a,
abstract = {{<p>Bio-based insulation materials, such as wood fibre, are gaining attention for their low embodied energy, biogenic carbon storage, and potential to leverage moisture-heat interactions to reduce building energy demands. An unexplored phenomenon that might influence their thermal behaviour is moisture sorption hysteresis, where moisture content depends on whether the material is adsorbing or desorbing water vapour, affecting latent heat and thermal conductivity. This study develops and evaluates a method to incorporate moisture hysteresis into commercial hygrothermal software (WUFI 6.5) by manually partitioning insulation layers into separate " desorption states" based on moisture history. Under controlled, steady-state conditions, modelling hysteresis yielded modest reductions (a few percent) in net heat flux, primarily by delaying evaporation to warmer periods. However, simulations of realistic Nordic wall assemblies with variable day-night conditions showed negligible overall energy performance improvements, as minor gains from moderated daytime thermal loads were largely offset by increased conduction due to higher moisture levels. While confirming the feasibility of modelling hysteresis in standard industry tools, the current approach remains cumbersome, highlighting the need for streamlined or automated methods. Further research is necessary to explore specific design or climatic conditions that may amplify hysteresis effects, refine modelling techniques, and conduct large-scale validation to improve the accuracy of bio-based insulation performance predictions in real buildings.</p>}},
author = {{Ranefjard, Oskar and Niklewski, Jonas and Rosenkilde, Anders}},
booktitle = {{Thermal Performance of the Exterior Envelopes of Whole Buildings XVI International Conference}},
isbn = {{9781964173344}},
issn = {{2166-8469}},
language = {{eng}},
publisher = {{American Society of Heating Refrigerating and Air-Conditioning Engineers}},
series = {{Thermal Performance of the Exterior Envelopes of Whole Buildings}},
title = {{The Influence of Moisture Hysteresis on the Thermal Performance of Bio-Based Insulation}},
url = {{http://dx.doi.org/10.63044/b16ran29}},
doi = {{10.63044/b16ran29}},
year = {{2025}},
}