Investigation of Heat and Moisture Performance of Alternative Insulation Materials

Investigations are carried out on some insulation products which are "alternative" to the ones that are traditionally used in Danish constructions. The alternative products are claimed to be friendly both to the environment and to the labour force. The materials investigated are: cellulose insulation, sheep wool, flax, and perlite. These materials, except for the last one, are very hygroscopic. The following investigations are carried out:
1. Experimental investigation of the thermal conductivity at different humidity conditions.
The thermal conductivity is determined for the different materials with a guarded hot plate apparatus in which different vapour pressure conditions can be maintained over the specimens.
2. Experimental investigation of the effect of natural convection on heat transfer.
Heat transfer is measured in full size walls with insulation of either cellulose or sheep's wool when installed
in a hot box/cold box facility. The dimension of the insulation's measuring area is 1000 mm width x 3000 mm height x appr. 400 mm thickness.
3. Computational analysis of the hygrothermal performance of constructions with alternative insulation products.
The hygrothermal performance of constructions with alternative insulation products is analysed with a computational model for combined heat and moisture transfer. The analysis concerns both traditional wall and roof constructions with the alternative insulation products, and some alternative designs prescribed by manufacturers of alternative insulation materials.
All three investigations are compared against similar results when mineral fibre is used.
The moisture transport properties of the materials (sorption, vapour transmission, and suction) are investigated in a companion project by the Department of Structural Engineering and Materials, DTU.