Big Dreams, Tight Budgets: UH Retro-Commissioning to Reduce Carbon Footprint
Authors: Sameer Kapileshwari, University of Houston Facilities and Cole Robison, Controls Unlimited
Using Physical Modeling to Refine Downwash Inputs to AERMOD at a Food Process...Sergio A. Guerra
Demonstrating compliance with air quality standards using dispersion modeling is increasingly difficulty because of significant tightening National Ambient Air Quality Standards (NAAQS) that has occurred in the last decade. Compliance with these standards is usually demonstrated using AERMOD, EPA’s standard model for assessing air quality impacts from industrial sources. However, AERMOD often produces higher predictions of air quality impacts due to the inherent conservative (high) assumptions and simplifications in its formulation. A specific situation involves the calculations used to assess the impacts of air flow downwash around buildings. Although the theory used to estimate these effects was developed for a limited set of building types, these formulae are applied indiscriminately to all types of buildings in a conservative fashion, often leading to significant overpredictions of downwash effects.
This presentation covers the basics of wind tunnel modeling and how it can be used to correct downwash induced overpredictions to achieve compliance. The presentation will also describe the setup and execution of wind tunnel modeling at a food processing facility to develop improved downwash parameters and increase the accuracy of dispersion modeling results.
Probabilistic & Source Characterization Techniques in AERMOD ComplianceSergio A. Guerra
The short term NAAQS are more stringent and traditional techniques are not suitable anymore. The probabilistic nature of these standards also opens the door to modeling techniques based on probability. Source characterization studies can also be used to refine AERMOD’s inputs to be more accurate and achieve reductions of more than half. This presentation will cover these compliance methods.
Currently, it is assumed that a given emission unit is in operation at its maximum capacity every hour of the year. However, assuming constant maximum emissions is overly conservative for facilities such as power plants that are not in operation all the time at full load. A better approach is the use of the Monte Carlo technique to account for emission variability. Another conservative assumption in NAAQS modeling relates to combining predicted concentrations from AERMOD with maximum or design concentrations from the monitor. A more reasonable approach is to combine the 50th percentile background concentration with AERMOD values.
The inputs to AERMOD can be obtained by more accurate source characterization studies. Such is the case of building dimensions commonly calculated with BPIP. These dimensions tend to overstate the wake effects and produce significantly higher concentrations especially for lattice structures, elongated buildings, and streamlined structures. An Equivalent Building Dimensions (EBD) study can be used to inform AERMOD with more accurate downwash characteristics.
Are you trying to reduce energy consumption on your campus? Conservation programs that include building retrofits and improvements to metering and controls can reduce energy consumption by over 20% on university and college campuses.
David Helliwell and John Metras, University of British Columbia’s Managing Director of Infrastructure Development presented a 45 minute webinar on reducing energy consumption on campus.
This presentation includes:
• An overview of UBC’s ECOTrek project and the keys to its success in reducing energy consumption across the campus
• An explanation of the role of EMS (Energy Management Systems) in ensuring the persistence of energy savings
• An outline of UBC’s future energy sustainability projects
John Metras was the Director of Operations for UBC when the university implemented its $35M ECOTrek project that involved rebuilding and retrofitting the infrastructure of nearly 300 buildings, and which led to a 23% reduction in campus energy consumption and a 15% reduction in greenhouse gas emissions.
David Helliwell has worked in the energy sector since 1994, including a role with the Canadian government where he was responsible for reducing costs and improving environmental performance of 700 million square feet of office space across the country. He is the CEO of Pulse Energy, which he co-founded in 2006.
Diesel backup generators are commonly installed in hospitals, data centers, universities, hotels, and other businesses for use in the event of power disruptions. These engines have quick response times that provide an unmatched reliable source of emergency backup power. Facilities that have these backup engines can also benefit from enrolling in demand response (DR) programs that offer economic incentives to participants who volunteer the use of their backup generators to supply electricity to the grid during certain periods of high electricity demand. In recent years, there has been an increase in the number of backup engines that have enrolled in DR programs in exchange for economic incentives. DR programs provide grid reliability, especially during periods of high electricity demand. Therefore, this is a win-win situation for backup engine owners and power utility companies offering these incentives. Generally, a backup generator with a capacity of 500 kilowatt (kW) or more is necessary to participate in DR programs. Participants in these DR programs agree with the local power company to use their backup engines when directed; usually during periods of peak electricity demand or power disruption. However, recent air quality regulations that apply to backup generators can be challenging to meet when participating in a DR program. That is the case because the applicable requirements for backup engine depend on whether the use is strictly for emergency purposes or for DR (considered non-emergency). Purely emergency use engines are subject to work practice standards while non-emergency engines are subject to emission limits that may require emission controls. Additionally, non-emergency engines may be subject to dispersion modeling requirements to show compliance with the national ambient air quality standards (NAAQS). At the moment the dispersion model used in permitting evaluations is extremely conservative and can show compliance issues. In conclusion, DR programs can be a profitable way to get additional cash for owners and operators of backup engines. However, the permitting implications should be considered thoroughly before enrolling in such a program to avoid any unintended adverse consequences.
We are a young company promoted by IIT Alumni. We provide services which helps individuals and organizations to take the "Green Route" for cleaner future. Our services includes Energy Audit, EPCM for Renewable energy (Solar & Bio-mass) Projects, Technology Evaluation (Research & Analysis) and carbon management services(footprint, mitigation and branding)
Evaluating AERMOD and Wind Tunnel Derived Equivalent Building DimensionsSergio A. Guerra
While the current EBD method is the best available option to determine correct building dimensions in the model, a different method was suggested by EPA in the 2011 Memo: Model Clearinghouse Review of EBD for AERMOD.9 Attachment B to the 2011 Memo includes an assessment of the Alcoa Davenport Works EBD Study. In this evaluation EPA compared wind tunnel observations with AERMOD derived concentrations. However, this evaluation has important shortcomings. First, to carry out this comparison between wind tunnel and AERMOD concentrations, it is necessary to collect velocity profiles that include longitudinal and vertical turbulent intensity measurements upwind of the stack. These data were not available for the EPA evaluation of the Alcoa Davenport Works EBD Study. Second, the wind tunnel model operating conditions were converted to full scale conditions by using exact similarity. However, exact similarity is not used to specify model operating conditions since only momentum ratios are matched but not buoyancy ones. Whereas EPA did not provide important details on how this study was performed, this paper outlines how to properly carry out this new method where AERMOD is used to determine equivalent building dimensions. The viability of this new method was also evaluated and discussed.
Industrial energy efficiency - approaches, technologies and policies, Girish ...ESD UNU-IAS
This lecture is part of the 2016 ProSPER.Net Young Researchers’ School on sustainable energy for transforming lives: availability, accessibility, affordability
Updates on Policy and Codes - BREEAM, Part L, MEES & BB101IES VE
This presentation was given by Bruce Elrick, Consultancy Operations Manager at IES, at Spaces Study Day in Manchester on 15th June 2018.
Find out about upcoming IES events here: https://www.iesve.com/discoveries/category/event
Using Physical Modeling to Refine Downwash Inputs to AERMOD at a Food Process...Sergio A. Guerra
Demonstrating compliance with air quality standards using dispersion modeling is increasingly difficulty because of significant tightening National Ambient Air Quality Standards (NAAQS) that has occurred in the last decade. Compliance with these standards is usually demonstrated using AERMOD, EPA’s standard model for assessing air quality impacts from industrial sources. However, AERMOD often produces higher predictions of air quality impacts due to the inherent conservative (high) assumptions and simplifications in its formulation. A specific situation involves the calculations used to assess the impacts of air flow downwash around buildings. Although the theory used to estimate these effects was developed for a limited set of building types, these formulae are applied indiscriminately to all types of buildings in a conservative fashion, often leading to significant overpredictions of downwash effects.
This presentation covers the basics of wind tunnel modeling and how it can be used to correct downwash induced overpredictions to achieve compliance. The presentation will also describe the setup and execution of wind tunnel modeling at a food processing facility to develop improved downwash parameters and increase the accuracy of dispersion modeling results.
Probabilistic & Source Characterization Techniques in AERMOD ComplianceSergio A. Guerra
The short term NAAQS are more stringent and traditional techniques are not suitable anymore. The probabilistic nature of these standards also opens the door to modeling techniques based on probability. Source characterization studies can also be used to refine AERMOD’s inputs to be more accurate and achieve reductions of more than half. This presentation will cover these compliance methods.
Currently, it is assumed that a given emission unit is in operation at its maximum capacity every hour of the year. However, assuming constant maximum emissions is overly conservative for facilities such as power plants that are not in operation all the time at full load. A better approach is the use of the Monte Carlo technique to account for emission variability. Another conservative assumption in NAAQS modeling relates to combining predicted concentrations from AERMOD with maximum or design concentrations from the monitor. A more reasonable approach is to combine the 50th percentile background concentration with AERMOD values.
The inputs to AERMOD can be obtained by more accurate source characterization studies. Such is the case of building dimensions commonly calculated with BPIP. These dimensions tend to overstate the wake effects and produce significantly higher concentrations especially for lattice structures, elongated buildings, and streamlined structures. An Equivalent Building Dimensions (EBD) study can be used to inform AERMOD with more accurate downwash characteristics.
Are you trying to reduce energy consumption on your campus? Conservation programs that include building retrofits and improvements to metering and controls can reduce energy consumption by over 20% on university and college campuses.
David Helliwell and John Metras, University of British Columbia’s Managing Director of Infrastructure Development presented a 45 minute webinar on reducing energy consumption on campus.
This presentation includes:
• An overview of UBC’s ECOTrek project and the keys to its success in reducing energy consumption across the campus
• An explanation of the role of EMS (Energy Management Systems) in ensuring the persistence of energy savings
• An outline of UBC’s future energy sustainability projects
John Metras was the Director of Operations for UBC when the university implemented its $35M ECOTrek project that involved rebuilding and retrofitting the infrastructure of nearly 300 buildings, and which led to a 23% reduction in campus energy consumption and a 15% reduction in greenhouse gas emissions.
David Helliwell has worked in the energy sector since 1994, including a role with the Canadian government where he was responsible for reducing costs and improving environmental performance of 700 million square feet of office space across the country. He is the CEO of Pulse Energy, which he co-founded in 2006.
Diesel backup generators are commonly installed in hospitals, data centers, universities, hotels, and other businesses for use in the event of power disruptions. These engines have quick response times that provide an unmatched reliable source of emergency backup power. Facilities that have these backup engines can also benefit from enrolling in demand response (DR) programs that offer economic incentives to participants who volunteer the use of their backup generators to supply electricity to the grid during certain periods of high electricity demand. In recent years, there has been an increase in the number of backup engines that have enrolled in DR programs in exchange for economic incentives. DR programs provide grid reliability, especially during periods of high electricity demand. Therefore, this is a win-win situation for backup engine owners and power utility companies offering these incentives. Generally, a backup generator with a capacity of 500 kilowatt (kW) or more is necessary to participate in DR programs. Participants in these DR programs agree with the local power company to use their backup engines when directed; usually during periods of peak electricity demand or power disruption. However, recent air quality regulations that apply to backup generators can be challenging to meet when participating in a DR program. That is the case because the applicable requirements for backup engine depend on whether the use is strictly for emergency purposes or for DR (considered non-emergency). Purely emergency use engines are subject to work practice standards while non-emergency engines are subject to emission limits that may require emission controls. Additionally, non-emergency engines may be subject to dispersion modeling requirements to show compliance with the national ambient air quality standards (NAAQS). At the moment the dispersion model used in permitting evaluations is extremely conservative and can show compliance issues. In conclusion, DR programs can be a profitable way to get additional cash for owners and operators of backup engines. However, the permitting implications should be considered thoroughly before enrolling in such a program to avoid any unintended adverse consequences.
We are a young company promoted by IIT Alumni. We provide services which helps individuals and organizations to take the "Green Route" for cleaner future. Our services includes Energy Audit, EPCM for Renewable energy (Solar & Bio-mass) Projects, Technology Evaluation (Research & Analysis) and carbon management services(footprint, mitigation and branding)
Evaluating AERMOD and Wind Tunnel Derived Equivalent Building DimensionsSergio A. Guerra
While the current EBD method is the best available option to determine correct building dimensions in the model, a different method was suggested by EPA in the 2011 Memo: Model Clearinghouse Review of EBD for AERMOD.9 Attachment B to the 2011 Memo includes an assessment of the Alcoa Davenport Works EBD Study. In this evaluation EPA compared wind tunnel observations with AERMOD derived concentrations. However, this evaluation has important shortcomings. First, to carry out this comparison between wind tunnel and AERMOD concentrations, it is necessary to collect velocity profiles that include longitudinal and vertical turbulent intensity measurements upwind of the stack. These data were not available for the EPA evaluation of the Alcoa Davenport Works EBD Study. Second, the wind tunnel model operating conditions were converted to full scale conditions by using exact similarity. However, exact similarity is not used to specify model operating conditions since only momentum ratios are matched but not buoyancy ones. Whereas EPA did not provide important details on how this study was performed, this paper outlines how to properly carry out this new method where AERMOD is used to determine equivalent building dimensions. The viability of this new method was also evaluated and discussed.
Industrial energy efficiency - approaches, technologies and policies, Girish ...ESD UNU-IAS
This lecture is part of the 2016 ProSPER.Net Young Researchers’ School on sustainable energy for transforming lives: availability, accessibility, affordability
Updates on Policy and Codes - BREEAM, Part L, MEES & BB101IES VE
This presentation was given by Bruce Elrick, Consultancy Operations Manager at IES, at Spaces Study Day in Manchester on 15th June 2018.
Find out about upcoming IES events here: https://www.iesve.com/discoveries/category/event
Energy Management Strategies for MURB & Commercial BuildingsEnercare Inc.
Enercare’s 3rd annual Thought Leadership event series, Energy Management: What’s New and What’s Next, explores energy conservation opportunities, the latest technologies and regulations shaping the multi-residential and commercial building management space.
You can’t manage what you don’t measure. This presentation by PL Consulting Corp will cover the use of energy audits and hydro bill analysis to understand the equipment and energy usage in your building. Energy audits, which include financials such as cost savings, incentives and estimated capital costs, equip building operators to make informed decisions on equipment replacement and operational adjustments. In addition to better understanding your building, this presentation will cover conservation measures such as intuitive automated controls which can effectively and significantly reduce overall consumption and increase your bottom line.
Presented by: Konrad Seemann, CEM, CBCP, PL Consulting Corp
Research Associate Dr Callum Rae discusses
the challenges presented by the growth in the
Energy Centre market, and outlines our alternative
approach to Energy Centre design, which has
successfully been applied to the AECC Energy
Centre project.
As the highly prestigious London Wall Place
project approaches completion of the shell
and core, Director, James O’Byrne reviews the
project and the application of BIM, and discusses
the various benefits on the overall design and
coordination process.
Diesel fuel is now a Category 3 flammable liquid.
Technical Board Director Wyn Turnbull reports
on the impact to diesel storage and use, as the
result of the recent Classification, Labelling and
Packaging of Chemical (CLP) Regulations 2015
which have replaced the now revoked CHIP
Regulations.
Associate Director Paul Scriven provides a brief
overview of the WELL Building Standard and
discusses why and how its popularity is growing.
Finally, Group Director Robert Thorogood discusses
how far standardisation of controls and automation
have developed using the IEC 61850 integration
standard, and what the benefits may bring to the
control of power distribution.
Paul Flatt, Group Chairman and CEO,
Hurley Palmer Flatt.
A printed circuit board (PCB) is a fundamental component in modern electronics that serves as a platform for assembling and connecting electronic components. It provides a solid foundation for the interconnection of various electronic elements, including integrated circuits (ICs), resistors, capacitors, and other passive and active components.
The construction of a PCB typically involves a thin board made of non-conductive material, often fiberglass reinforced with epoxy resin or other laminates. The surface of the board is coated with a layer of copper, which serves as the conductive material for the electrical pathways.
PCB design involves a meticulous layout of conductive traces, which form the pathways for electrical signals to flow between components. These traces are usually etched onto the copper layer through a process of chemical etching or mechanical milling. The layout of the traces is determined by the circuit schematic, aiming to minimize signal interference, optimize signal integrity, and ensure efficient electrical connectivity.
In addition to the conductive traces, a PCB features various other elements. These include pads and vias. Pads are small areas of exposed copper where electronic components are soldered onto the board. Vias are holes drilled through the board that connect different layers of the PCB, facilitating the routing of traces between them.
PCBs can have multiple layers, ranging from single-sided boards with components mounted on one side, to double-sided and multi-layer boards, which have components mounted on both sides and multiple layers of conductive traces sandwiched between insulating layers.
The manufacturing process for PCBs involves several steps, including design and layout, fabrication of the board itself, application of the copper layer, etching or milling of the traces, drilling of holes for components and vias, and finally, assembly of components onto the board through soldering or other methods.
PCBs are essential in a wide range of electronic devices, from simple consumer electronics like calculators and remote controls to complex systems like computers, smartphones, and medical equipment. Their compact design, reliability, and scalability make them indispensable in the world of modern electronics, enabling the creation of increasingly sophisticated and efficient electronic devices.
Engagement Coordinator Megan Hoye gave a presentation on CEE's research projects to the American Institute of Architects Minnesota's, Committee on the Environment.
Paul Hamilton, Schneider Electric: Lean and Clean: Equipping Modern Manufactu...guest3e1229f
On Friday, March 19, Alliance staff and industry experts discussed energy efficiency's role in reducing greenhouse gas emissions in the industrial sector.
Paul Hamilton, Schneider Electric: Lean and Clean: Equipping Modern Manufactu...Alliance To Save Energy
On Friday, March 19, Alliance staff and industry experts discussed energy efficiency's role in reducing greenhouse gas emissions in the industrial sector. http://ase.org/content/article/detail/6517
CEE and Seventhwave lead a rapid-fire discussion of innovative tech and program approaches, and the most meaningful recent research findings for utility representatives, efficiency program implementers, and both residential and commercial field experts.
Experts explain new multifamily auditing techniques, their scalability, what makes the energy savings cost-effective, where the programs can be most successful, and what non-energy benefits result from this work.
Similar to Kapileshwari and Robison- Gulf Coast Green 2010 (20)
Gulf Coast Green 2010 Rives Taylor & Richard JohnsonHayley Pallister
Gulf Coast Green speakers, Rives Taylor & Richard Johnson, presented "Looking Long: Striving for Sustainable Texas Campus Communities" on 4/16/2010 in Houston, Texas
Gulf Coast Green speakers, Tim Duggan and Ritchie Katko, presented " Making it Right: A Progress Report on Recovery in New Orleans" on 4/15/2010 in Houston, Texas
MD Anderson Energy Initiatives, reduced annual energy costs by $1 million in 2009
Author: Timothy Peglow, MD Anderson Cancer Center, Patient Care and Prevention Facililties
Dive into the innovative world of smart garages with our insightful presentation, "Exploring the Future of Smart Garages." This comprehensive guide covers the latest advancements in garage technology, including automated systems, smart security features, energy efficiency solutions, and seamless integration with smart home ecosystems. Learn how these technologies are transforming traditional garages into high-tech, efficient spaces that enhance convenience, safety, and sustainability.
Ideal for homeowners, tech enthusiasts, and industry professionals, this presentation provides valuable insights into the trends, benefits, and future developments in smart garage technology. Stay ahead of the curve with our expert analysis and practical tips on implementing smart garage solutions.
7 Alternatives to Bullet Points in PowerPointAlvis Oh
So you tried all the ways to beautify your bullet points on your pitch deck but it just got way uglier. These points are supposed to be memorable and leave a lasting impression on your audience. With these tips, you'll no longer have to spend so much time thinking how you should present your pointers.
Unleash Your Inner Demon with the "Let's Summon Demons" T-Shirt. Calling all fans of dark humor and edgy fashion! The "Let's Summon Demons" t-shirt is a unique way to express yourself and turn heads.
https://dribbble.com/shots/24253051-Let-s-Summon-Demons-Shirt
Book Formatting: Quality Control Checks for DesignersConfidence Ago
This presentation was made to help designers who work in publishing houses or format books for printing ensure quality.
Quality control is vital to every industry. This is why every department in a company need create a method they use in ensuring quality. This, perhaps, will not only improve the quality of products and bring errors to the barest minimum, but take it to a near perfect finish.
It is beyond a moot point that a good book will somewhat be judged by its cover, but the content of the book remains king. No matter how beautiful the cover, if the quality of writing or presentation is off, that will be a reason for readers not to come back to the book or recommend it.
So, this presentation points designers to some important things that may be missed by an editor that they could eventually discover and call the attention of the editor.
Between Filth and Fortune- Urban Cattle Foraging Realities by Devi S Nair, An...Mansi Shah
This study examines cattle rearing in urban and rural settings, focusing on milk production and consumption. By exploring a case in Ahmedabad, it highlights the challenges and processes in dairy farming across different environments, emphasising the need for sustainable practices and the essential role of milk in daily consumption.
1. Big Dreams Tight Budgets: UH retro-commissioning to reduce Carbon footprint Presented at Gulf Coast Green - 2010 April 15, 2010 University of Houston Houston, TX
US DOE reports that buildings account for 72% of US electricity consumption and 40% of US CO2 emissions. More than half of the commercial buildings built before 1980 (when energy codes largely did not exist) have yet to undergo energy related retrofit, representing enormous opportunity to reduce building energy consumption.
Definition Existing-building commissioning, also known as retro-commissioning, is an event in the life of a building that applies a systematic investigation process for improving or optimizing a building’s operation and maintenance. It may or may not emphasize bringing the building back to its original intended design. The retro-commissioning process most often focuses on dynamic energy-using systems with the goal of reducing energy waste, obtaining energy cost savings, and identifying and fixing existing problems .
Cameron Cameron is a two story building that is split into two halves serving separate schools. The west half is a single story and the east half has two stories. There are two main air handlers which are served by separate outdoor air handlers. The smaller of the two air handler serves 9 mixing boxes in the west half while the larger air handler serves 22 mixing boxes on two floors of the east half. This building utilizes a dual duct scheme for conditioning purposes. The air handlers are not equipped chilled water valves and instead control discharge temperature through reheat. This building is unique in that it is the only building of the five to have its own chillers and boilers. There are two, identical, 70 ton, air-cooled chillers each served by a 5HP pump. A single boiler provides hot water to the air handlers for reheat. Technology Technology is a single story building that is served with hot and chilled water by the central plant. There is a single VFD-controlled chilled water pump and a constant speed hot water pump. AHU #3 is a dual duct unit serving 10 mixing boxes in the east side of the center of the building. The remaining three air handlers are VAV units with variable frequency drives and chilled water coils only; they supply a total of 18 VAV boxes equipped with hot water reheat. Engineering By far the largest building in this study, Engineering is comprised of 3 floors and a basement. The original AHUs include two rooftop outdoor air units, two AHUs on each of the 3 floors, and seven AHUs in the basement. The six main AHUs, two per floor, are all three duct systems. There is the main cold duct, and then a central zone hot duct, and a perimeter zone hot duct. The AHUs serve the zones with mixing boxes. The basement air handlers are mixed between single and multi-zone. AHU B1, B2, B5, and B7 are all dual duct design with mixing boxes at the zones. AHU B3 and B4 are single zone air handlers. AHU B6 is the only AHU with a single duct that serves VAVs with hot water reheat. The two rooftop units, R1 and R2, are the original outdoor air units that supply all of the air handlers within the building. Each is equipped with a VFD which is controlled by a static pressure setpoint. When the University recently installed additional exhaust fans to serve the laboratory space, seven single zone, constant speed, OAHUs were added at the same time; three on the third floor that serve the atrium and four in the basement. Combined, there is 81,000 cfm of outdoor air continuously supplied from nine OAHUs for ventilation and make-up air for the fume hoods. Hot and chilled water for the handlers is supplied from two chilled water pumps and one hot water pump located in the basement. The roof-mounted exhaust fans are organized into multiple fan systems that gang together multiple exhaust ducts. The system provides redundancy should one of the fans fail. There is one 3-fan system that only uses two fans at a time and four 2-fan systems that run one fan at a time. The exhaust fans are run 24 hours a day and are constant volume. Communications The Communications and Wortham buildings share chilled and hot water pumps . There is a single 7.5 hp hot water pump and two parallel 40 hp chilled water pumps. There are two main air handlers; AHU 10 is on the second floor and AHU 9 is on the first. These are variable volume with VFD fan motors. AHU 10 draws untreated outdoor air through a vent on the roof while AHU 9 receives pretreated outdoor air from an outdoor air unit, OAHU 11, located in the same mechanical room as AHU 10. There are two smaller AHUs, 12 and 13, that are single zone, constant volume with no outdoor air intake. There are seven hot water fan coil units that provide additional heating to the perimeter zones when it is needed. The air handlers operate from 5am to 11pm daily. Wortham Wortham is composed mainly of a 566 seat auditorium that is served by two single zone, variable volume air handlers. AHU 7 serves the stage area and AHU 8 serves the seating area. There is a large scenery shop located behind the stage that is served by the single zone, variable volume AHU 1. The classrooms and workshops in the rest of the building are served by multi-zone variable volume AHUs 2-5 with the exception of the single zone, constant volume AHU 4 which serves a large classroom. There is no AHU6. The air handlers operate from 5am to 11pm daily.
2.1 Change Preheat Setpoint for Cameron OAHU 1 The hot water valve for this outdoor air handler was set to heat the incoming air to 90°F no matter what the outdoor temperature. University staff lowered this setting to 55°F. A picture of the pneumatic control box is seen in Figure 1. 2.2 Communications OAHU Schedule Because this building was already on a DDC system with time of day scheduling in place, university staff only had to change the schedule of the units associated with ventilation to 8am-5pm. 2.3 Wortham OAHU Schedule This measure is similar to the previous one. The schedule for units associated with ventilation was changed to 8am-5pm. 2.4 Communications Exterior Lights For this measure it was determined that the DDC point was never correctly mapped to control the exterior lights. The most cost effective way to implement this measure was to put the circuits on a mechanical time clock.
Engineering Lighting This measure was implemented through the use of a mechanical time clock. This would allow the unnecessary lights to be turned off at night. Without the use of photocells, no peak savings will be achieved, but annual savings will be present. Add Ceiling Fans to Wortham It has a 15 foot diameter and uses a 2 HP motor. This “low velocity, high volume” fan will enable the fan speed on the 7.5 HP motor to be reduced to only what is required to heat and cool the space. Prior to these fans being installed, the fan was run at 100% speed all day long. Reduce Engineering Outdoor Air The bypass dampers on the exhaust fans systems were repaired or retro-fitted with dampers and actuators so they can modulate to maintain a static pressure set point. New airflow measuring stations were installed to measure both the bypass airflow through the new dampers as well as the outdoor airflow into the building through the rooftop units R1 and R2. The designed building pressure will be maintained by only reducing the incoming outdoor airflow by an amount equal to the airflow through the bypass dampers. Figure 12 shows one of the existing bypass dampers that were retrofitted. Figure 13 shows the trending of the VFD speed for OAHU R1 and R2. The building ventilation system is quite complicated and will take a while to fine tune. Notice that one of the units is running much faster than the other. This is most likely due to the position of the largest of the exhaust fans is on that side of the building which would require more ventilation air. It is a positive sign that the other OAHU is now running in the 20 to 40% speed range which yields significant savings.
Demand Controlled Ventilation for Cameron New actuators and dampers were installed on the outdoor air handlers for Cameron. Outdoor airflow into the building will be controlled in three stages based upon CO2 measurements and setpoints: outdoor air damper closed, damper open fan off, and damper open fan on. As the CO2 measurements begin to rise, the damper will open to allow the main air handler to pull a small amount of fresh air through the open damper. If the CO2 levels continue to rise, the fan for the outdoor air handler will turn on to increase airflow. The hot and chilled water valves on the outdoor unit will continue to condition the air so long as the damper is open. Please note that the University of Houston decided to replace the chilled water coil on OAHU 1 during the process of implementing this measure. Figure 15 shows the new outdoor air damper for OAHU 2. Figure 16 and Figure 17 show a week long trend of the CO2 concentration and the damper position. Notice that the damper closes outside of the normal building occupancy schedule and is at 10% a majority of the time. If the CO2 concentration rose above the setpoint the damper opens to 100% as shown in Figure 16. Also note in Figure 16 that the CO2 level is getting much lower than the minimum expected, 350 ppm. This sensor has since been recalibrated. Reset VFDs to Automatic A contract for a set number of hours was given to solve as many of the VAV issues as possible. The automatic control for all of the listed air handlers has been reinstated which allows the VFDs to vary the speed of the fan motor with the building load. The speed of the VFDs has been trended to show the changes and can be seen in Figure 19. Technology DDC A new DDC system was installed for this building to replace the antiquated pneumatic system. Points were added to control and monitor the fans motors for all air handlers and exhaust fans as well as the discharge air temperature of the air handler units. This new system also allowed the university to schedule the units to turn off at night when the building is unoccupied. Figure 21 shows the new controls cabinet for the building. The box has the capacity to add addition points onto it, such as VAV boxes or room temperature sensors, in the future. Figure 22 through Figure 27 show the runtime logs for AHUs 1, 2, 3, and 4 as well as the hot and chilled water pumps. These show the equipment turning off and on at the specified times. The first few times may be skewed as the schedules were just being set up and tested. Cameron DDC Similar to the previous measure, a new DDC system was installed for this building to replace the antiquated pneumatic system. Points were added to control and monitor the discharge air temperature, status of the fans motors for all air handlers and exhaust fans, as well as status and control for the pumps and chillers. This new system also allowed the university to schedule the units to turn off at night when the building is unoccupied. The status of these fans was logged to show when the fans turned off and on. Figure 28 shows the supply temperature from OAHU 2. The occupied mode can be seen in the tight oscillations around the temperature setpoint of 53°F. During the unoccupied mode, the temperature trends more smoothly and moves toward the outdoor temperature. It has been suggested to tweak the PID loop for the chilled water valve to correct these rapid movements. Figure 30 and Figure 31 show the runtime logs for AHUs 1 and 2. These show the air handlers turning off and on at the specified times. The first few times may be skewed as the schedules were just being set up and tested. A picture of one of the new CO2 sensors is shown below.