Energy Efficiency in Multi-Tenant Office Buildings

Transcription

1 Energy Efficiency in Multi-Tenant Office Buildings Presented by David Herman, PE, LEED AP Principal, EnerG Associates, LLC 3/10/2015 1

2 Learning Objectives 1. List the principal sources and uses of energy in existing multi-tenant office buildings. 2. Identify energy-savings opportunities in existing multi-tenant buildings. 3. Understand the potential for savings through costeffective building upgrades. 4. Recognize the value of the ENERGY STAR score as a tool to understand a building s energy performance. 3/10/2015 2

3 Outline Building Energy Use Profile ENERGY STAR Score Building Energy Use Savings Building Energy Efficiency Measures Typical Office Building Example Building Stakeholders 3/10/2015 3

4 Building Energy Use Profile Average Office Building Consumption per Energy Use Intenstiy Square Fool (kbtu/sf) Cost per Square Foot Electricity 15.5 kwh/sf 53.0 $1.60 Natural Gas 0.27 therms/sf 26.8 $0.31 Total 79.8 $1.91 3/10/2015 4

5 Building Energy Use Profile Average Office Building 3/10/2015 5

6 Building Energy Use Profile Average Office Building 3/10/2015 6

7 Building Energy Use Profile According to the Department of Energy, energy use is the largest operating expense in office buildings. The cost of maintenance and repairs is a close second. 3/10/2015 7

8 ENERGY STAR Score What is the ENERGY STAR score? The ENERGY STAR score is a 1-to-100 assessment of a building s energy efficiency, as compared with similar buildings nationwide. The score adjusts for climate and business activity. To qualify as an ENERGY STAR certified building, a building must be verified to earn a score of 75 or higher, indicating that the building performs better than at least 75% of similar buildings nationwide. 3/10/2015 8

9 Building Energy Use Savings Improve energy use 30% -- amount of energy the average commercial building wastes 10% -- reduction of energy use with little or no cost 2.4% -- annual reduction of energy use for buildings that benchmark their energy use on a regular basis, on average 3/10/2015 9

10 Building Energy Use Savings A savings of 2.4% for three consecutive years is equivalent to the following for a 500,000 square foot office building: Cumulative energy cost savings -- $120,000 Increase in asset value -- over $1 million 3/10/

11 Benchmarking Savings 3/10/

12 Building Energy Efficiency Energy efficiency: one step at a time Upgrades should be made throughout the entire property NOT just in common areas. A phased approach can help with financing and reduce any tenant inconvenience. 3/10/

13 Building Energy Efficiency Building recommissioning Lighting Building envelope Fans and motors Heating and cooling systems Controls 3/10/

14 Building Recommissioning Recommissioning is a systemic, documented process. Ensures building systems are operating according to the design intent, as well as the current needs of property owners and occupants. Identifies energy-saving opportunities. Recommissioning is an on-going process. 3/10/

15 Lighting Lighting upgrades offer a quick payback and an enhanced visual environment. Upgrading from T12 fluorescent lamps with magnetic ballasts to higher-efficiency T8 lamps with electronic ballasts can yield savings up to 25%. 3/10/

16 Building Envelope Upgrade and seal walls, roofs and windows. Improves occupant comfort. Reduces heating and cooling costs. Ensure insulation levels match recommendations in ASHRAE 90.1 Energy Standard for Buildings Except Low-Rise Residential Buildings. 3/10/

17 Fans and Motors Converting constant volume systems to variable air volume units can reduce air flow by 40%. Installing variable speed drives can lower fan speed and reduce energy use by up to 50%. 3/10/

18 Heating and Cooling Systems Upgrading to more energy-efficient furnaces, boilers and air conditioning systems can reduce energy costs by up to 15%. Ensuring new energy-efficient systems are right-sized further saves energy. An oversized energy-efficient system will continue to waste energy. 3/10/

19 Controls Building energy-management system Programmable thermostats Occupancy sensors 3/10/

20 Tenant Involvement Get everyone involved. Optimizing efficiency requires cooperation between building management and tenants. Education is key. Conserving energy benefits everyone. Form an energy team. Establish energy-saving goals. Implement a strategy. 3/10/

21 Typical Office Building Example Baseline Building High-rise office building Chicago, IL 250,000 SF/800 occupants/900 computers 7 AM-6 PM Mon-Fri (55 hours per week) Centrifugal chiller/gas-fired hot water boiler 3/10/

22 Typical Office Building Example O&M/Recommissioning Measures Optimize temperature set points Optimize HVAC scheduling Optimize ventilation to minimum required for code Chilled water reset controls Implement janitorial best practices Power management enabling for PCs, printers and copiers Turn off plug loads at night Specify ENERGY STAR equipment-office equipment, vending machines 3/10/

23 Typical Office Building Example Lighting Measures Efficient lighting (high-performance T8/T5s, CFLS, LED exit signs) Occupancy sensors Perimeter daylighting controls 3/10/

24 Typical Office Building Example All Measures All O&M/recommissioning measures All lighting measures High-efficiency chillers Variable speed pumps and fans Premium efficiency motors 3/10/

25 Typical Office Building Example Scenario Elec Use (kwh) Elec Savings (kwh) Elec Savings (%) Nat Gas Use (therms) Nat Gas Savings (therms Nat Gas Savings (%) Baseline 3,760, , O&M 3,306, ,000 12% 90,500 19,000 17% Lighting 3,471, ,000 8% 112,900-3,400-3% All Measures 2,483,000 1,277,000 34% 98,100 11,400 10% Scenario Peak Demand (kw) Demand Reduction (kw) Demand Reduction (%) Baseline 1, O&M 1, % Lighting 1, % All Measures % Scenario Annual EUI (kbtu/sf) EUI Reduction (%) Eenrgy Cost ($) Energy Savings ($) EPA Energy Rating Baseline 95 - $482, O&M 81 15% $418,946 63, Lighting 93 3% $455,092 26, /10/2015 All Measures 73 23% $340, ,

26 Building Stakeholders Building owner Property manager Tenant 3/10/

27 Building Stakeholders Tenant Reduce total cost of occupancy Owner Increase net operating income Increase return on investment 3/10/

28 Key Points Investing in energy efficiency increases asset value and makes available space more attractive. A phased approach to efficiency upgrades can help with financing and reduce tenant inconvenience. Optimizing energy savings requires a collaborative effort between property managers and tenants. 3/10/

29 To download a copy of this presentation, visit 3/10/