energy design resources design brief options and opportunities Summary Not all energy efficiency measures When focus is placed on the largest energy uses in a particular are appropriate for all building types type of building incorporating pertinent enhancements in a but some are especially useful for standard design can readily improve energy efficiency This Design Brief summarizes the energy efficiency design strategies that offer the greatest potential benefit in 11 building types Although some of the measures discussed in this brief are frequently employed others are seldom considered during the particular buildings This Design Brief reminds designers and builders of opportunities they should consider in each of their projects design process This quick overview of energy efficiency strategies appropriate to different types of buildings will allow design contents ers to place a range of potentially useful options on the table early in the decision making process Energy intensity is presented as an indicator of the potential for cost effective energy efficient design strategies in a particular building type Introduction 2 Energy Cost Intensity and Energy Use Intensity 2 Energy Efficiency Design Strategies for New Construction 4 Schools 6 Large Offices 8 Small Offices 10 Single Story Tilt Up Retail Outlets 12 Department Mall and Free Standing Retail Stores 14 Grocery Stores 16 High Rise Residential Buildings 18 Hotels and Motels 20 Laboratories 22 Hospitals 24 Warehouses 26 Introduction Numerous reports and briefs are aimed at providing the building community with information to improve the energy efficiency of the buildings where we work shop live and learn Although much practical wisdom is contained in this vast literature its very magnitude and breadth make it difficult for designers to judge which of many options may apply to a specific design job Opportunities to save energy in buildings are a function of how much energy they use in the first place Consequently before focusing on specific energy saving measures it is useful to understand how much energy various types of buildings typically consume Energy Cost Intensity and Energy Use Intensity Energy cost intensity is the annual cost of energy used per square foot Energy cost intensities discussed in this Design Brief are derived from eQUEST an Energy Design Resources energy modeling software program In general as energy cost intensity increases energy efficient design strategies become more cost effective Figure 1 shows the range of Figure 1 Approximate cost intensity ranges for different building types in California Energy cost intensities for various building types are derived from eQUEST an Energy Design Resources energy modeling software program Actual cost intensities vary based on occupancy usage location and building Schools Large offices Small offices Single story tilt up retail outlets Department mall and free standing retail stores Grocery stores High rise residential buildings Hotels and motels Laboratories Hospitals Warehouses 0 1 2 3 4 5 Energy cost intensity range square foot year 6 7 8 Source Constructive Technologies Group CTG Energetics Inc page 2 options and opportunities energy cost per square foot in different building types The figure shows that in general energy efficient designs are especially cost effective in laboratories hospitals and grocery stores Energy use intensity is the amount of energy per square foot a building uses annually from all metered sources Energy use intensity is useful in comparing energy use in buildings of different sizes and occupancies The pie charts presented with each building type show energy use intensity The charts which are discussed in the introduction to each section can be used to compare energy use in different building types Table 1 summarizes many of the most cost effective energy design strategies according to their energy use intensity Cells in Table 1 that are completely filled in represent strategies that will target the most energy intensive uses in a given building type Implementing these strategies has the most potential for minimizing unnecessary energy use in the building type On the other hand cells that are completely clear indicate that this strategy will probably not significantly affect overall energy use in the finished building Table 1 Energy efficiency measures for specific building types For each building type energy efficiency measures are categorized according to their ability to minimize energy use Measures Large Small Schools offices offices Department mall and High rise Single story free standing residential Grocery tilt up retail retail stores buildings stores Hotels and motels Laboratories Hospitals Warehouses High efficiency lighting Occupancy sensors Efficient parking lot lighting Automatic lighting controls Skylights and photocell controls Exterior shading Cool roof High efficiency HVAC Direct digital controls Variable speed drives Demand controlled ventilation Direct indirect evaporative cooling Water heating heat recovery Highest potential Some potential Least potential options and opportunities Source CTG Energetics Inc page 3 Energy Efficiency Design Strategies for New Construction Table 1 lists many of the energy efficient design strategies that are discussed throughout this Design Brief The following sections give brief descriptions of these strategies Specific applications of these strategies are discussed under the building types where they are most applicable Building envelope measures The skin of a building should provide an appro priate barrier between interior and exterior environments Reflective surfaces especially on roofs and walls will minimize the amount of solar heat that penetrates a building In particular Energy Star compliant cool roofs reflect a large portion of the sun s heat energy back into the atmosphere Optimized thermal insulation is essential to buffer the interior of the building from the fluctuating temperature outside In general Title 24 insulation requirements provide this optimization Exterior shading such as horizontal overhangs and vertical fins is a good way to decrease the amount of solar gain into a building and can also enhance the exterior design of the structure In particular shading fenestration from direct solar radiation has great potential to lower the cooling requirements of a building Two energy efficiency strategies can be accomplished through glazing selection Lower solar heat gain
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