Forest companies across Canada are interested in using laser scanners for scaling logs because it has potential for reducing scaling costs. Scanning logs over bark requires a method to obtain the under-bark diameter in order to calculate the solid wood volume. This report evaluates the methods of applying a bark factor to determine under-bark diameter. It also identifies new scanner scaling technologies for measuring bark thickness.
This literature review aims to provide a general picture of retrofit needs, markets, and commonly used strategies and measures to reduce building energy consumption, and is primarily focused on energy retrofit of the building envelope. Improving airtightness and thermal performance are the two key aspects for improving energy performance of the building envelope and subsequently reducing the energy required for space heating or cooling. This report focuses on the retrofit of single family houses and wood-frame buildings and covers potential use of wood-based systems in retrofitting the building envelope of concrete and steel buildings.
Air sealing is typically the first step and also one of the most cost-effective measures to improving energy performance of the building envelope. Airtightness can be achieved through sealing gaps in the existing air barrier, such as polyethylene or drywall, depending on the air barrier approach; or often more effectively, through installing a new air barrier, such as an airtight exterior sheathing membrane or continuous exterior insulation during retrofit. Interface detailing is always important to achieve continuity and effectiveness of an air barrier. For an airtight building, mechanical ventilation is needed to ensure good indoor air quality and heat recovery ventilators are typically required for an energy efficient building.
Improving thermal resistance of the building envelope is the other key strategy to improve building energy efficiency during retrofit. This can be achieved by: 1. blowing or injecting insulation into an existing wall or a roof; 2. building extra framing, for example, by creating double-stud exterior walls to accommodate more thermal insulation; or, 3. by installing continuous insulation, typically on the exterior. Adding exterior insulation is a major solution to improving thermal performance of the building envelope, particularly for large buildings. When highly insulated building envelope assemblies are built, more attention is required to ensure good moisture performance. An increased level of thermal insulation generally increases moisture risk due to increased vapour condensation potential but reduced drying ability. Adding exterior insulation can make exterior structural components warmer and consequently reduce vapour condensation risk in a heating climate. However, the vapour permeance of exterior insulation may also affect the drying ability and should be taken into account in design.
Overall energy retrofit remains a tremendous potential market since the majority of existing buildings were built prior to implementation of any energy requirement and have large room available for improving energy performance. However, significant barriers exist, mostly associated with retrofit cost. Improving energy performance of the building envelope typically has a long payback time depending on the building, climate, target performance, and measures taken. Use of wood-based products during energy retrofit also needs to be further identified and developed.
This study addressed biomass availability, harvesting, transportation, and chipping costs for the production of bioenergy in the Teslin region of Yukon. It revealed that significant volumes of standing timber below 20 cm in diameter at breast height (DBH) exist that could be utilized for bioenergy. These volumes, however, would sustain only small electricity generation capacities; however, a more efficient solution would be to utilize the biomass in district heating applications. The study also estimated harvesting, transportation, and chipping costs of low- and high-mechanized systems. These costs will have to be further validated and incorporated into an investment calculator to assess the feasibility of future bioenergy projects in Teslin.
Attracting, retaining and training labor is a challenge for forest operations in North America. FPInnovations attended the Pacific Logging Congress (PLC) in November 2015 where one of the technical sessions focused on attracting and retaining people to the industry, in particular to contractor operations. The majority of the strategies presented in this Info-Note were suggested by logging contractors presenting at the PLC. A few others gleaned from other sources were added as well.
Attirer, retenir et former la main-d’œuvre représentent des défis pour les opérations forestières d’Amérique du Nord. FPInnovations a assisté au Pacific Logging Congress (PLC) en novembre 2015, dont l’une des sessions portait sur les meilleures pratiques pour attirer et retenir les employés dans l’industrie, en particulier pour les entrepreneurs. La majorité des stratégies présentées ici ont été adoptées par les entrepreneurs forestiers qui faisaient une présentation au PLC. Nous en avons ajouté quelques autres obtenues d’ailleurs.
There is uncertainty regarding the effectiveness of using caulk boots vs. non-caulk hiking boots in silviculture work in the interior of British Columbia. WorkSafeBC regulation 8.23, states “caulked or other equally effective footwear must be worn by workers who are required to walk on logs, poles, pilings or other round timbers”, but does not specifically require caulk boots to be worn on steep slopes. Caulk boots are used almost exclusively by silviculture workers in coastal B.C. but are not commonly used in interior B.C. even though there are many situations where they may provide superior traction. Instead, workers in interior B.C. have a preference for non-caulk hiking boots. Workers will often select their boots based on personal preference rather than on information about the boot’s traction performance. Additional information regarding the differences in the traction of caulk boots and non-caulk hiking boots on various forest ground surfaces would help most workers make better-informed choices. Understanding the differences in traction is one of the most important factors when selecting a work boot in any situation and is especially true in the hazardous ground conditions of forest workers. For this reason, FPInnovations constructed a testing apparatus designed to measure and compare the static coefficient of friction of caulk boots and non-caulk hiking boots on four common types of ground cover surfaces in B.C. forests.
Canadian Forest Service researchers are working to estimate forest productivity at different spatial scales. Variations in productivity are best appreciated at the tree and stand level in productivity.
Les chercheurs du Service canadien des forêts travaillent à estimer la productivité forestière à différentes échelles spatiales. C’est à l’échelle de l’arbre et du peuplement que s’apprécient le mieux les variations dans la productivité.
Transformative Technologies Program identifierSeries Energy Efficiency of Advanced Building Systems
The largest source of energy consumption and greenhouse gas emissions in Canada and around the world is buildings. As a consequence, building designers are encouraged to adopt designs that reduce operational energy, through both increasingly stringent energy codes and voluntary green building programs that go beyond code requirements. Among structural building materials, wood has by far the lowest heat conductivity. As a result it is typically easier to meet certain insulation targets (e.g., thermal transmission and effective thermal resistance) with wood-based wall systems when following current construction practices. Good envelopes greatly contribute to energy efficient buildings. However, there are many factors in addition to building envelope insulation levels that affect the operational energy of a building. This study aims to provide designers with information which will assist them to choose energy efficient exterior wall systems by providing energy consumption estimates for an archetypal 6-storey residential building. Comparisons were made among several exterior wall systems including light wood-framing, cross-laminated timber (CLT), steel-stud framing, and window walls, for a range of structural systems including structural steel, light wood-frame, CLT, heavy timber, and concrete. The opaque exterior wall assemblies targeted meeting the minimum thermal requirements based on the National Energy Code of Canada for Buildings (NECB. NRC 2011). A 3-D method was used to calculate effective R-values of these exterior walls by taking into account all thermal bridging, in comparison with a parallel-path flow method in compliance with the NECB. Three glazing ratios, including 30%, 50%, and 70%, and two efficiency levels for Heating, Ventilation, & Air Conditioning (HVAC) systems, termed basic HVAC and advanced HVAC, were also assessed. Whole-building energy consumption was simulated using EnergyPlus. Four climates, from Zone 4 to Zone 7, with cities of Vancouver, Toronto, Ottawa, and Edmonton to represent each climate, were selected in this study. The energy assessment was conducted by Morrison Hershfield.
A comparison of operational energy consumption among these different exterior wall systems for this archetypal 6-storey building has shown that accounting for thermal bridging is critically important for improving thermal performance of building envelopes. Wood-based systems including light wood-frame walls, CLT, and wood-framed infill walls in concrete structures have inherently lower thermal bridging compared with other systems, such as steel-frame walls in steel and concrete structures, or window walls in concrete or timber structures. Conclusions are provided for specific climates and cities in Section 4.2. General conclusions and highlights are summarized as follows:
Building envelope influences only the energy required for space conditioning. The space heating energy consumption ranged between 28% and 49% of the entire building energy consumption, when the basic HVAC type was used, for the four cities assessed in this study. An efficient HVAC system would further reduce the proportion of space heating energy consumption. The rest of the energy is used for hot water and electrical appliances etc.
Compared to the NECB-compliant calculation, the 3-D method showed a greatly reduced effective R-value of the opaque wall assemblies due to thermal bridging. Steel-stud wall assemblies showed much larger reductions in effective R-values than wood-based wall assemblies.
Wood-based walls in a light wood-frame building, or a CLT building, would improve building energy efficiency, with total energy savings ranging from 3% to 9%, compared to a concrete building with steel-stud walls, depending on the HVAC type and the glazing ratio, when the 3-D method was used for calculating thermal resistance. The energy savings were higher in colder climates, such as Toronto, Ottawa, and Edmonton, than in Vancouver.
The use of wood-frame infill wall in concrete structure improved the whole building energy efficiency by up to 6% depending on the climate, relative to the use of steel-stud infill walls, under the same HVAC (basic or efficient type) and glazing ratio (30% or 50%).
Concrete structures typically have much higher glazing ratios than wood buildings. The wood-framed building, with exterior-insulated walls meeting the thermal insulation requirements and at a glazing ratio of 30%, showed whole-building energy savings of about 13-18%, compared to a concrete structure with window walls at a glazing ratio of 70%.
Simply adding insulation (e.g., exterior insulation) in a building envelope while ignoring thermal bridging is not the most effective way to improve building energy efficiency.
The thermal bridging at window transitions greatly reduced the effective R-values of the opaque walls and consequently the whole-building energy efficiency. The higher the glazing ratio was, the larger the impact would be. Window wall with a high glazing ratio would further reduce building energy efficiency, compared with regular windows.
The energy efficiency of the HVAC system used in a building had the largest impact on the whole-building energy efficiency, compared to the impacts caused by exterior wall systems, glazing ratios, or thermal bridging at various details.
The energy efficiency measures studied in this report delivered higher energy savings in colder climates, such as Montreal, than in warmer climates, such as Vancouver.
It is recommended that future effort be put into further developing tools for practitioners to account for thermal bridging more conveniently.
Despite the oscillations in the price of fuel at the pump, it continues to rise. Five years ago, fuel accounted for 30% of transportation costs. Today, that proportion is estimated to be at least 40%, and the forecasts are not optimistic. It is therefore crucial to look at the factors that can influence fuel consumption and and how to reduce it. The team of researchers from the Transportation and Energy program of FPInnovations program is working on this issue and is analyzing various possible solutions.
Malgré les oscillations du prix du carburant à la pompe, ce dernier ne cesse d’augmenter. Il y a cinq ans, le carburant représentait 30% des coûts de transport. Aujourd’hui, cette proportion est estimée à au moins 40 %, et les prévisions ne sont pas optimistes. Il est donc crucial de regarder les facteurs qui peuvent influencer la consommation de carburant et les moyens de la réduire. L’équipe de chercheurs du programme Transport et Énergie de FPInnovations travaille sur la question et analyse différentes pistes de solutions.
Several thousand hectares of non-commercial softwood forests are thinned each year in Eastern Canada. Although this intervention is justified by the logic of reducing competition between stems, thus competition between stems, thus favouring the growth of residual trees, few studies with quantitative data on the long-term effects of thinning of precommercial thinning (PCT) are available. How does this treatment actually influence tree growth? What are the long-term impacts on fiber quality and quality and value of the fiber?
Plusieurs milliers d’hectares de forêts résineuses non commerciales sont éclaircis chaque année dans l’Est du Canada. Bien que cette intervention soit justifiée par la logique de diminuer la compétition entre les tiges, favorisant ainsi la croissance des arbres résiduels, peu d’études comportant des données quantitatives sur les effets à long terme de l’éclaircie précommerciale (EPC) sont disponibles. Comment ce traitement influence-t-il réellement la croissance des arbres? Quelles sont les incidences à long terme sur la qualité et la valeur de la fibre ?