Energy efficiency 

 

Miami meets and exceeds Ohio HB 251 goal of 20% energy reduction.

Ohio House Bill 251, ORC 3345.69 (HB 251) was signed into law in January 2007 and mandated that each institution of higher education develop a plan to reduce energy consumption by at least 20% by the end of FY2014 compared to FY2004 as a benchmark year, measured in Thousand British Thermal Units (kbtus) per Gross Square Foot (GSF)

Due to efforts on the Oxford, Hamilton, Middletown and VOA campuses, Miami reported an impressive reduction of 22% by the end of FY 2014 (June).   Total energy density on all campuses in FY2014 was 128.1 kbtu/gsf  vs. 163.9 kbtu/gsf in FY2004.  

Miami was able to achieve the goal despite seeing both a hotter summer(17.4%) and a colder winter(12.7%) as compared to the baseline year.

Miami's gross square footage over this same time period increased 26.8% over 1.5 million sq. ft..  Even with this added square footage Miami uses less total energy than it did in 2004.   1,036,532 MMBtu FY2014, compared to 1,045,962 MMBtu in FY2004. 

While water was separately evaluated, it should be noted that water consumption in hundred cubic feet per GSF (CCF/GSF) also decreased YoY by 33.9% in FY 2014 as compared to FY 2004.

How did we accomplish the HB 251 goal, soon after the legislation was passed Miami formed an Energy Sub-committee of the Sustainability Committee.  Individuals on the sub-committee were all within Physical Facilities Department and meet monthly starting in 2009 until mid-year 2014 to strategize on ways to achieve the energy reduction. 

There were 5 key areas that were the focus on reducing energy.  These were:

1.  Building Automation & Enhancements

2.  RetroCommissioning

3.  Energy Awareness

4.  Energy Efficiency Projects

5.  Performance Contracting

 

Building Automation & Enhancements

 

The Building Automation System (BAS) controls major HVAC equipment in many of the buildings on campus, along with schedule control of the majority of outdoor lighting and some indoor lighting. There are 417 field panels in place for control of HVAC systems, Chiller Plants, alarm monitoring of critical environments, and lighting control.  Under these field panels reside approximately 7,298 floor level package controllers and the current physical database is approaching 230,789 points. These devices control VAV boxes, Cabinet unit heaters, fan coils, lab controllers, and other equipment designed for comfort control.  The BAS team implemented the following energy saving strategies to fully utilized the capabilities of the control system.

 

South & North Chiller Plant

         Installed Chiller Optimization Programming.

 

Building Occupancy Zones and Special Event Scheduling

Event and zone scheduling is being used to control equipment in each building. 

A new unoccupied control strategy was put in place, to provide energy savings through setback/setup programs while still providing a safety net for equipment during severe outdoor temperature swings. 

Bathroom exhaust fans will shut down during the unoccupied periods.

 

Residence Halls Building Occupancy Schedules

         Setback programs were created for residence hall buildings, controlled by DDC equipment, to set all rooms in the building to an unoccupied temperature set point utilizing one command. . 

Fixed Summer/Winter zone Set point standards

Fixed zone set point control was put in service in February of 2009. The heating set point will be allowed to float between 70-74 deg.f. and during the cooling season the range is 72-74 deg.f.

 

Chilled Water Pump Differential Pressure Optimization Control

 

Created programming to monitor chilled water valve position on all air handlers and adjust the differential pressure set point for pump speed control accordingly.

AHU Supply Air[1]  Temperature Set Point Reset Optimization

 

     Created programming to monitor hot water valve position on all VAV boxes associated with the respective air handler. All valves will be sampled and if the maximum valve position opens toward the 100% open position, the supply air set point at the air handler will be reset upward between the ranges of 55 and 63 deg.f.  Five minute sample times are recommended to reduce cycling.

  An example of the reset  is shown below:

Maximum valve position 100%                              AHU SUPPLY AIR SET POINT 62 DEGF.

Maximum valve position 20%                                AHU SUPPLY AIR SET POINT 55 DEG.F.

 

AHU SUPPLY FAN OPTIMIZATION

 

     Created programming to monitor VAV box damper position and reduce  the static pressure set point if the maximum damper position is less than 100%.  When a damper position is near 100% the SPS can be increased to insure the proper amount of airflow.  Five minute sample times are recommended to reduce cycling.

DDC VAV BOX REHEAT MINIMUMS AND MAXIMUM SETTINGS

 

     Adjusted the box parameters to all VAV controller applications so that the reheat minimum air flow matches the cooling min.  The existing reheat minimum (50% of the maximum flow setting) was used as the new reheat maximum.  When the box is at cooling minimum and the temperature in the space continues to fall towards the heating temperature set point, the control will switch from cooling to heating mode.  The flow set point will remain at the cooling minimum as the reheat valve begins to open.  When the reheat valve reaches 50% open, the control will adjust the air flow set point upward, tracking the valve as it continues to open, until the reheat maximum flow setting is achieved.

OUTSIDE AIR RESET OF HEATING HOT WATER TEMPERATURES CAMPUSWIDE

       Reduce the temperature of the Heating Hot Water circulated in the buildings as the outside air temperatures go up.  Typical reset schedule is

0 F outside air = 150 F Heating Hot Water Supply Temperature

70 F outside air = 110 F Heating Hot Water Supply Temperature

DEMAND CONTROL VENTILATION

     CO2 control in large spaces to insure only the necessary amount of outside air is brought into the space.  Spaces are typically maintained at 1000 ppm CO2 maximum

 

RetroCommissioning

The Campus has a large number of heating, ventilating, and air conditioning equipment, as well as chilled water utility plants and steam generation.  This equipment is controlled by a sophisticated Energy Management control system with numerous sensors and field devices.    The University already had PM programs in place and took corrective action based on work orders submitted for the HVAC equipment and controls.  Instead of being reactive the University create a RetroCommissioning team to tune up the equipment in the buildings.  A set of systematic procedures/checklist for reviewing each typical equipment was created and standardized to ensure consistency of work. The focus is on the buildings energy-using equipment such as Air handling units, pumps, heat exhangers, and controls.  Retrocommissioning identifies improvements to building controls and other low cost operational measures. In addition to the energy saving deficiencies it uncovers, retrocommissioning also has many non-energy benefits such as improved occupant comfort and productivity, better indoor air quality, and extended equipment life.

The process the University uses is key team members sit down with the building point of contacts and go over how the building HVAC systems are operating.  Areas covered are:

 

o     Operational Hours and HVAC Scheduling

o     Change of Use in Space/Graphics

o     Hot/Cold Complaint Areas

o     HVAC Noise Issues

    

Based on the feedback given, this information is shared with all members of the retrocommissioning team and action plans are generated to address items.  Two Air Quality Technicians then go out to each building and begin commissioning of major equipment.  Typical task are:

o     Calibrate/replace sensors

o     Calibrate and adjust valve and damper motors and linkage

o     Standard work process: Document findings (Pull Up the Check list)

o     Fix small  issues or create work orders

o     Review programming, does it have energy strategies implement as necessary

o     Weekly meetings are held with the team to discuss progress and talk about areas where we can improve efficiency and/or comfort

o     Compile documents and maintain records on a shared drive for future reference.

 

       Results

Retrocommissioning team started in the summer of 2013 and by the end of FY 14 the team had commissioned over 50% of the 3,569,669 square footage of E&G buildings in the first year. This achieved over $100,000 in energy savings alone in the first year.  Results have been between 6-25% energy reduction per building realized as a result of this work.  Improved customer service and building comfort levels also have realized along with a reduction in Hot/Cold complaint work orders.  The team has by the end of FY 15 completed all of the E&G buildings and has turned its focus on the Auxiliaries.

  

Energy Awareness Programs

       Residence Halls now have information cards explaining simple energy saving strategies

       Residence Halls also have cards explaining the proper way to operate the heating controls.

       Building heat steam valves are being shut off if the outside temperature is above 55F.

       Stickers for fume hood sashes were developed and placed on all hoods to encourage that all sashes be closed when not in use.

      Building Points of Contact focused on energy which has been incorporated into the retrocommissioning agenda.

Energy Efficiency projects

 

The Energy sub-committee laid out a blueprint on reduction goals needed to achieve the HB 251 goals.  Each member proposed project ideas on ways to save energy to meet the reduction goal, each one was vetted and project cost and energy savings were developed for each.  The projects with the shortest payback and the most significant energy savings impact were then prioritized for funding opportunities.  All told the committee developed and recommended project ideas and the University funded just over $2.2M in projects.  The projects specifically created are shown below:

Energy Efficiency Projects

 

 

Performance Contracting

The University contracted with an outside firm to perform Re-Commissioning of 6 buildings on the Oxford Campus along with all buildings on the Middletown and Hamilton Regional Campus's.  The contract value ended up at $718,820 and achieved a savings of $151,000 per year in energy cost.  The work was completed early in fiscal year 14 and energy conservation measures that were identified and implemented were the following:

Oxford Campus

       Hughes - Change Humidification from Constant 35% to Reset Schedule AHU-1 & 5-9

       Hughes:  Incorporate Unoccupied Set Back Schedule on AHU-9

       Hughes:  Shut Off AHU-10 Chilled Water Coil Pump When OAT>35F

       Hughes:  Implement Unoccupied Air Change Rate Set Back in Labs 272, 274 and 279

       Hughes:  Repair Humidifier Isolation Valve on AHU-1

       Hughes:  Correct RAF Operation and Open Smoke Damper

       Pearson:  Incorporate Global Economizer Control of AHU's with 65F-db Economizer Changeover

       Engineering:  Repair Humidifier Spray Nozzle on AHU-1

       Engineering:  Utilize Air-Side Economizer in lieu of DX when OAT is below 50 deg-F on AHU-5

       Occupancy Sensor Set Back Goggin AHU-7

        Hiestand: Repair Switch Serving Exhaust Fan EF-1 in Room 27 and Revise OAD Control

Middletown Campus

       Johnston Hall:  Unoccupied Setback Modification of AHU-1&2

       Johnston: Reduce OA Minimum and Utilize Existing DCV on AHU-3

       Johnston Hall:  AHU-1&2 Optimize MAT and DAT Set Points

       Johnston: Reduce OA Minimum and Utilize Existing DCV on AHU-1 and AHU-2

       Johnston: Replace Failed Hot Deck Control Valve on AHU-2

       Thesken: Repair OA Damper on AHU-1

       Finkelman: Combined Savings (Setback, VFD, Control Strategy)

       Gardner Harvey: Library HWP-1 Operation

       Gardner Harvey Library: Toilet Exhaust Fan Operation

       Gardner Harvey Library: Optimize MAT-DAT set-points: Ideal MAT = DAT less 2degF

       Gardner Harvey Library:  Repair RA Damper on AHU-1

       Gardner Harvey Library: Eliminate Subcooling on AHU-1

       Levey:  Incorporate Unoccupied Set Back Schedule on AHU-1

       Levey: Incorporate Demand Control Ventilation on AHU-1

       Levey Hall Optimize AHU-2 Heat Recovery

       Levey: Repair Fume Hood High Setting Override

       Levey - Chilled Water Plant - Optimization (lower CWT, lockout, secondary control)

Hamilton Campus

       Campuswide Boilers off at ambient > 85degF

       Campuswide VAV Modifications

       Campuswide Air Handling Unit Schedule Modifications

 

SUMMARY

The Chart below shows the progress the University made year by year in exceeding the 20% energy reduction goal.

 

Miami University HB-251 Progress Chart

FY 14 = 128.1 kbtu/gsf  vs. FY 04 = 163.9 kbtu/gsf


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