Straw insulation materials to address heating fuel requirements, thermal comfort, and natural resource depletion in developing regions

Abstract

In modem society, major stresses are placed on the natural environment in an attempt to make the location comfortable for the human occupants. For many developing regions with cold winters such as northern Pakistan, new building construction has been driven by structural and economic criteria. Thermal comfort can be improved, heating fuel requirements can be reduced, and degradation of the natural environment can be mitigated by improving the thermal performance of these buildings. This thesis presents strong evidence for the benefits of thermal insulation and presents an optimal solution for producing that insulation in a sustainable and cost-competitive manner. Using Polymeric Methylene Diisocyanate as a binder, we were able to develop a formula for low density, structurally sound, straw based insulation board. The fabrication process involves the spraying of isocyanate onto an agricultural furnish of mixed fiber lengths in a rotating drum. The process appears to be one that could be used in developing regions. It is likely that this board can be manufactured well below the cost of competing insulation board products on a unit thermal resistance basis. Forty-one experimental boards were fabricated. The thermal, structural, and economic characteristics of these boards have been tested and analyzed. A formula has been developed for an optimized solution based on binder load, fiber size concentrations, density, and economic cost. The optimal boards meet or exceed all of our product design specifications. The optimal insulation placement scenarios for community-built school buildings are explored through the use of a dynamic building thermal modeling software, SERI-RES. The work described in this thesis provides a strong foundation for moving ahead and improving the thermal performance of the schools. Installation of insulation will improve thermal comfort in schools that continue to be unheated or under-heated. For those schools that are more fully heated, insulation will reduce fuel use at no penalty in thermal comfort. Improved thermal comfort will extend the use of schools in winter and payback periods are of reasonable duration, from two to four years for heated schools.