"solar"

It’s a fact that buildings consume two thirds of all the electricity produced in North America and one third of all the energy produced in North America. While it is recognized that cooling and heating costs can be reduced by adding insulation under the roof surface, there is a diminishing return on the strategy of increasing insulation to conserve energy costs. This is where “cool roofing” can play a role in further reducing the energy consumed, and in minimizing the Heat Island effect created in the big urban cities. Cool roofing relies on the properties of reflectivity and emissivity of the roofing material. Reflectivity Reflectivity is the ability of the roof to reflect solar radiation back into the atmosphere. Its primary measure is solar reflectance - the proportion of the total solar radiation that is reflected back to the atmosphere. Any solar radiation that is not reflected is absorbed into the building envelope, requiring further energy to cool the building; or partially convected into the atmosphere increasing the ambient air temperature in the surrounding environment (Heat Island effect). The measure of reflectivity is the Solar Reflectance Index (SRI) which takes into account the properties of the material as well as the cooling effect of wind passing over the roof. The SRI for a low slope roof will be 0 for standard black (reflectance 0.05, emittance 0.90) and 100 for standard white (reflectance 0.80, emittance 0.90).

We built the world first Passivhaus CPD training facility / pub, this is the worlds most airtight pub at 0.07ach at 50 pa. This is a twin wall timber frame, it’s 450mm wide insulation Huntsman which is made of thousands of recycled plastic bottles. Huntsman also recycled 1 billion plastic bottles from the sea last year. We have a 7.2 KW system solar panels system that powers the building, it’s got MVHR Nilan. On the external façade we applied Passive Purple External which is airtight up to 0.03ach.

Buildings consume one-third of all energy and two-thirds of all electricity generated. Cool metal roofs can help reduce energy consumption by lowering cooling loads with their wide array of finishes, designs and colors.Cool metal roofs are energy-efficient. • The roof can have the greatest impact on the energy use of a building. On a typical summer afternoon, a light-colored, more reflective roof that reflects 80 percent of sunlight will stay about 310C (550F) cooler than a darker roof that reflects only 20 percent of sunlight, as reported by the Heat Island Group of the Lawrence Berkeley National Laboratory. • Cool metal roofs are an excellent option for commercial retrofit applications because they can be efficiently installed with above-sheathing ventilation, allowing heat to dissipate through the ridge vent in hot weather while acting as an insulating layer when it is cold. Metal roofs can result in as much as a 30 percent reduction in heat gain through the vented roof. • Metal roofs provide the optimal foundation for photovoltaic installations since the roof can be expected to last longer than the PV system it supports. • Wall and roof solar heat recovery systems can be integrated with steel cladding and used to provide air, water or process heating needs. • Cool metal roofing is available unpainted, with thermosetting coil-applied paint finishes, or with granular-coated surfaces. This family of roofing can achieve solar reflectance of over 70 percent, meeting the EPA Energy Star Roof Products Program performance criteria. • Emittance as high as 90 percent can be achieved for painted and granular-coated metal roofing. • Painted metal roofs retain 95 percent of their initial reflectance and emittance over time. They resist the growth of organic matter and shed dirt more readily than other materials. • Cool metal roofing can help to mitigate the Urban Heat Island Effect because of its high reflectance, which can reduce ambient air temperatures. Cool metal roofs are cost-effective. • Metal roofing has low life-cycle costs, making it the choice of many school, government, commercial, industrial and institutional building owners. • Due to its light weight per unit area, structural savings can be realized in a building when compared with heavier non-metal roofing alternatives. • For re-roofing projects, metal roofing can often be applied over the original roof, saving removal and disposal costs. • Metal roofing is fully recyclable when ultimately removed as part of building renovation or demolition, allowing it to credibly claim both recycled content and 100 percent recyclability by recognized definitions. The product’s recyclability also provides significant savings on construction removal and disposal costs.