DTE Energy Taking Control of your Rooftop Units- Retrofitting RTU Controls Presented by
Agenda Why focus on Rooftop Unit (RTU) Controls? Common Energy Saving Measures Case Study Midwest High School HVAC Control Recommendations Energy Saving Results Contact Us/ Q&A
Why Focus on RTU Controls? HVAC can be more than 50% of Total Building Energy Usage Retro-commissioning is a systematic process to improve an existing building s performance through the identification of operational improvements that will increase occupant comfort and/or save energy. Can often resolve problems that occurred during design or construction and address problems that have developed throughout the building s life. Typical energy savings between 3-10% of total building energy use. Rooftop Units are the most common HVAC equipment in use.
Common Energy Saving Measures Control System Variable Frequency Drive (VFD) Demand Control Ventilation (DCV) Advanced Digital Economizer Control (ADEC). Variable Compressor Speed Optimal Compressor Sequencing Scheduling
Case Study Small Private Academy Located in the Great Lakes Region 11 RTUs 3 VAV units (31 classroom zones), 8 CAV units (Gym, offices, cafeteria) Limited Control System for VAV units. T-stat only for CAV units Unexplained run-away energy consumption for 10 months
Energy Usage Challenges 2017 Runaway energy usage No indication No central control Limited Scheduling
HVAC Control Recommendations Problem No central control single control panel for 3 RTUs, other T-stats throughout the building. No Indication No graphic display of equipment or operating setpoints No Scheduling RTUs running 24/7, even during summer break. Solution Web-based wireless controls allows access to all RTU controls at once from anywhere Easy to use mobile app displays realtime economizer position, temperature data, heat/cool set points 365-day scheduling allows after school or special events to be added at any time.
Projected Energy Savings Energy Conservation Measure Energy Saved (kwh/year) Annual Cost Savings Night Setback (VAV) 8,565 $685 Night Setback (CAV) 1,215 $97 Schedule AHU-3, 4 (VAV) 23,769 $1,902 Schedule AHU-5 (VAV) 12,631 $1,010 Schedule AHU-6 (CAV) 18,252 $1,460 Schedule AHU (CAV) 80,144 $6,411 Total Savings 144,575 $11,566 Additional Gas Savings $1,976
Other Energy Saving Measures
EDSS is an approved Service Provider Energy Design Service Systems (EDSS) is an approved service provider of the DTE Energy Retro-Commissioning (RCx) Program and a nationally certified energy consultant, providing comprehensive building energy efficiency related services. Nationwide Reach- EDSS serves all 50 states, Puerto Rico, the U.S. Virgin Islands, and even International Engineers, Architects, Lighting Designers, and Energy Specialists on staff Working with clients nationwide to offer custom lighting, energy and incentive solutions
EDSS
David Ely, President/CEO (810) 227-3377 davidely@edssenergy.com Janet Lawrence Sr. Engineer (810) 227-3377 jlawrence@edssenergy.com