the newsletter of tbd consultants - 3rd qtr 2014
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Wearable Computers & Construction
Wearable Computers & Construction
If you think computers have become invasive, you ain't seen nothing yet! In this article we look at wearable computers, and how they may become part of our lives in the construction industry.
We seem to be taking a long time to dig ourselves out of the economic hole we fell into, but it looks like we are well on the way. Here we develop a little progress report.
California Tightens Energy Controls
California’s Title 24 Energy Efficiency Standards were updated effective from January 1, 2014, and continue the push for energy reductions and reduction of the reliance on oil, which will hopefully improve the situation in regard to global warming.
The biggest changes relate to electrical work in commercial buildings, and trying to ensure that energy is not being used unnecessarily. Motion sensors and dimming controls are now required to dim fixtures in corridors and stairwells when no motion is detected. They are also required in aisles and open spaces of warehouses, reducing lighting levels by at least 50% when unoccupied. Egress lighting must be shut off outside of normal occupied times, although offices are allowed to have lighting on designated paths of egress, but at reduced levels. Full range dimming and associated controls are required for most fluorescent and LED fixtures, and the central lighting control system is to have demand response control (load shedding) ability. Daylight harvesting controls are required for all interior spaces where over 120W of load is within the daylit zone, providing ‘adaptive lighting’ that automatically dims or shuts off when not required.
Outside of the buildings, motion sensors are required on site lighting pole fixtures mounted under 25’ above finished grade. Motion sensors and daylight harvesting controls are now required in parking structures to dim fixtures when daylight is adequate or no motion detected. Residential buildings are required to have high-efficacy sources, vacancy sensors and controls in bathrooms. Retrofit projects must meet new-construction lighting standards for lighting power density (LPD) and dimming requirements if 10% or more of the lighting is being changed or 40 or more ballasts are being replaced.
Demand response (DR) is now required in all commercial buildings with floor areas of 10,000 SF or more (previously it was only required for retail spaces with sales floors over 50,000 SF). These systems automatically reduce light energy use to at least 15% below the building’s maximum lighting power in response to a DR signal from the utility company.
On commercial buildings, the lighting and lighting controls requirements can add around 20% to the lighting package, or about 7% to the overall electrical section. Changes to metering and receptacle load controls, such as demand response control and plug load control (automatic shut-off control for task lighting, etc., in office areas) adds around 10% to electrical distribution costs, or 1.5% to 2% to the overall electrical section.
Title 24 changes also affect the mechanical sections, and those changes include new requirements for fan control and integrated economizer (packaged units 6 tons and up must be VAV), and for fan control for fractional motors. There are also increased minimum equipment efficiencies required on chillers and cooling towers, and increased acceptance testing requirements for HVAC sensors and controls, along with automatic demand shed control requirements. These changes can add around 5% to mechanical costs.
Other changes include increased fenestration and air barrier requirements (to reduce solar gains, increase visual light transmittance, and to limit air leakage rates except in mild climates), and minimum wall and roof insulation requirements, along with increased low-slope cool roof requirements (to give increased reflectance). There are also increased mandatory requirements for computer rooms and data centers, refrigeration systems in supermarkets and warehouses, and laboratory exhaust VAV and heat recovery systems. Commercial buildings are required to be solar ready, third party design review is required during design, and there are additional commissioning requirements.
Assuming that the electrical systems account for about 12.5% of the construction cost, and mechanical account for about 17.5%, the overall effect of these Title 24 changes result in additional construction costs of around 2%.
Design consultant: Katie Levine of Vallance, Inc.