Spontaneous combustion of hog piles can result in inventory losses and potential damage to surrounding infrastructure and equipment. In April and June 2016, FPInnovations and Terminal Forest Product Ltd. conducted a study to investigate the use of thermal infra-red digital cameras to examine the thermal dynamics of a coastal hog fuel pile. They also investigated the feasibility of using thermal imaging to help develop better fire risk mitigation solutions.
This is a discussion paper addressing the factors involved when considering the total environmental footprint of wood doors. The discussion is within the context of a new amendment to BC energy regulations affecting doors and the subsequent market shifts that will occur as a direct result. The energy regulation applies a U-value threshold to doors. U-value is a physical (thermal) property of an assembly indicating the rate of conductive heat flow through the assembly. A maximum U-value for doors is being specified in BC that cannot be met by the current commonly-manufactured configuration for solid wood doors. In this paper, a life cycle assessment (LCA) approach is used to discuss the broader environmental picture beyond the single criterion of U-value, specifically focusing on the trade-off between embodied energy in a product and the impact of that product on the operating energy of the building in which it is installed. Any change to the current manufacturing process for wood doors for the purpose of improving thermal characteristics should be done within an LCA perspective so that the changes don’t inadvertently lead to a net increase in total lifetime energy consumption. Similarly, any market shift to non-wood alternatives for doors should also be done within an LCA perspective for the same reason. A detailed and precise analysis of door footprints requires LCA data and energy simulation results, both of which are beyond the scope of this study. In place of full LCA data, we accessed existing literature and existing partial LCA data (from the Athena Institute) to roughly estimate the embodied energy differences between door types, and to discuss the other environmental impacts of a substitution from today’s common wood doors to non-wood alternates. Three generic door types were compared: wood, steel and fibreglass. In all the environmental metrics examined, including embodied energy, the wood doors have the lowest impact. Although insulated steel and fibreglass doors typically have a lower U-value than wood doors, they involve more energy consumption in their manufacturing. This means that the added energy investment in steel and fibreglass doors will require some time to be paid back through reductions in a home’s heating and cooling costs. Similarly, an improvement to wood doors to reduce U-value may increase the embodied energy, requiring a payback period that may or may not be reached within the lifetime of the door.
A number of provincial governments may in the future taken proactive steps to make thermal efficiency requirements for fenestration products mandatory. A leader in the area of regulations, B.C. has enacted its Energy Efficiency Act which has stipulated that all exterior doors must have a thermal efficiency or U value of 2.0 W/m²
K. In addition, Energy Star requirements for the thermal performance of doors have recently been reduced to a point that no solid wood exterior door can meet these voluntary, well publicized standards. Foam-filled steel and fibreglass doors can easily meet current requirements and expected future tougher requirements when announced. Both mandated and voluntary thermal performance requirements will reduce the market share of Canadian exterior wood door manufacturers to a point that it would drive many of them out of business.
Following the lead of German wood door manufacturers with their success in manufacturing thermally efficient wood doors capable of meet very stringent German thermal efficiency standards, similar approaches were used in this project to develop thermally efficient wood prototype doors that incorporate the use of insulation in the door’s core. Three types of insulation were sourced which are proven to work in improving the thermal efficiency of door. A leading wood door manufacturer with experience in building fire doors was contracted to build eight prototype doors using similar construction techniques found with manufacturing fire doors.
Wood doors with insulation incorporated into doors are capable of exceeding government thermal performance requirements. Depending on both the thermal conductivity of the insulation used and its coverage within the door, the thicker proto-type doors were able to meet an Energy Star Zone D rating — the coldest climate in Canada. This is equal to the thermal performance rating attained by the best of competing foam-filled steel doors.
By adapting their wood door designs to incorporate the use of insulation in the door cores, Canadian wood door manufacturers can regain lost market share taken from them by foam-filled steel and fibreglass doors.
The main objective of this research is to contribute to the stream of research under way in Canada at the present time on the performance of exterior wall systems. In the process, we will facilitate the continuing and appropriate use of lumber and wood-based panel materials.
