Hygrothermal Simulation Seminar Presentations
A seminar to discuss simulation methods for hygrothermal assessment of traditional building construction was held on 12th September 2011.
Insulation retrofit of traditional buildings – Do we know what we are doing?
Hygrothermal simulations of stone walls and insulation retrofits
Heat loss through the components of the thermal envelope of buildings, such as walls, windows and roofs, has received widespread attention in recent years, vis-à-vis increasingly stringent regulations, proprietary standards, a growing focus on fuel poverty, new insulation systems and grant-aided insulation retrofit programmes. The moisture performance of such building components has received comparatively little attention. However, the two physical processes, heat transfer and moisture transfer, are strongly interdependent. This coupled heat and moisture performance is also described as hygrothermal performance.
This topic is particularly relevant to the retrofitting of traditional buildings. Construction materials and techniques used in the past were often permeable to both air and moisture. A quite typical type of wall construction for Scotland is a solid stone wall, bedded in lime mortar and finished internally with lime plaster on laths. Retrofitting such building components with new materials, for example, by adding insulation, can fundamentally change the building physics within the original fabric. The commonly used Glaser assessment method (e.g. used in BuildDesk) is only of limited applicability to mass stone walls. However, with recently developed advanced simulation programs, such as WUFI and Delphin, it is now possible to better predict retrofit measures on the performance of the building fabric.
However, do we actually know how accurately these programs work when simulating traditional construction? Do we know enough about traditional materials and insulation system to be able to simulate these realistically?
An evening seminar was held to provide an easy-to-understand introduction to hygrothermal building physics. The presentations from the seminar can be found below. Seminar Programme [pdf, 318kb]
Speaker Presentations Carsten Hermann, Historic Scotland - Hygrothermal Simulation Seminar - Introduction [pdf, 1.61 mb] Chris Sanders, Glasgow Caledonian University - Dewpoint to WUFI [pdf, 1mb] Joseph Little - Insulation Retrofit of Traditional Buildings - Do we know what we are doing? [pdf, 2mb] Manfred Kehrer - Hygrothermal Simulation & Measurement [pdf, 2.11mb]
Kruti Gandhi - Investigations of the hygrothermalperformance of stone walls in the North Wales climate by modelling and physical monitoring [pdf, 2.62mb]
A new Technical Paper will soon be published - 'Technical Paper 15 - Assessing insulation retrofits with hygrothermal simulations: Heat and moisture transfer in insulated solid stone walls'