Miami University
IN-47: Innovation A

The Miami University Goggin Ice Center is a 170,000 square-foot auxiliary facility built in 2006. It is dedicated to meeting the diverse recreational needs of its patrons: students, staff, athletes, the greater Oxford community, and visitors from across the country. It contains two NHL-size (200'x 85') ice sheets and a 3,200 seat arena, plus a second smaller ice sheet with seating for 250. It has locker room facilities for both the hockey and synchronized skating programs, in addition to 13 other locker areas.

The primary goal of the Goggin Ice Center is to promote and enhance wellness in the lives of Miami students, guests, and community members.

Here we present the technical background of the Goggin Ice Center conversion project:

We recognize that this innovative large-scale project is replicable only at other universities that have ice arenas. Ice arenas tend to be very energy-intensive. We show that converting an ice arena off carbon-intensive steam is feasible, reduces energy use, emissions, and costs, and provides an ROI.

Miami University’s Utility Master Plan (2012-2026) will result in the conversion of nearly every building on its Oxford campus from steam heat and hot water to geothermal, heating hot water (HHW) or heating hot water/simultaneous heat and cooling (HW/SHC). In fiscal year 2019 Miami made more energy systems conversions than any other year. One innovative project, included as part of Miami’s campus-wide conversion, was converting the Goggin Ice Center from steam to HHW (Heating/hot water) heating and cooling.

The energy efficiency upgrades to Goggin Ice Center were part of a larger steam to hot water conversion projects that converted 14 buildings in Miami University’s south quad and provided plant and site infrastructure to 5 additional residential halls that were being converted during the course of the project as part of large renovation projects.

Goggin Ice Center steam to hot water conversion presented considerable obstacles to the larger south quad hot water conversion goal. Namely, the desiccant dehumidifying air handlers use steam to dry the desiccant wheel and low-temperature hot water desiccant options are not common in the ice arena market. The project sought to address this obstacle and find other energy-saving solutions within the ice arena. A study was conducted to determine if there would be a return on investment for the additional energy savings solutions possible with the Goggin conversion as well as study different methods of heating the desiccant wheels for dehumidification. * The project team studied low-temperature desiccant solutions, energy recovery within the locker rooms, and energy recovery of the ice plant.

The Project Included: Equipment to convert the building systems from steam to hot water (pumps, heat exchangers, etc.); Three new desiccant air handlers to dehumidify the large ice pad/arena and a smaller ice pad; A heat recovery chiller to capture waste heat from the ice plant; An energy Recovery unit to serve the varsity locker room. Smaller pumps, accessories, controls, piping, and duct were also included to support these system changes.

We found that rejected heat from the ice plant could be captured and the temperature boosted via a heat recovery chiller rather than relying on the evaporative condensers. This offered energy savings with an attractive payback.

The desiccant air handlers could use either gas fired burner, electric fired heater or hot water to dry the desiccant wheel. After studying several different options and different hot water temperatures, we found that new desiccant air handlers could dry the air using lower temperature hot water (140 F) coupled with more regen air flow (CFM). The lower temp, but higher airflow balanced the dehumidification equation allowing for the desiccant to work at lower temperatures. This solution offered a place to use the once wasted heat from the ice plant within the building.

We found that energy recovery ventilators could be added to condition the locker rooms rather than using rink air. The locker rooms could have their ventilation air and conditioned air requirements satisfied using 100% outdoor air ran through an energy recovery ventilator. The energy recovery ventilator allowed the energy in the exhaust air to be transferred to the outdoor air through a total energy wheel. In addition to using less energy, this also allowed the amount of outdoor air being brought into the ice arena to be reduced during non-event days. The new ice arena air handlers would incorporate demand control ventilation as well as an event mode / non-event mode programming to satisfy the outdoor air ventilation requirements further saving energy.

First was to convert the Goggin Ice Center off of steam by the end of summer 2019. 2. Another goal was that the humidity levels in the ice arena were to be commensurate or superior than the previous humidity levels in the ice pad. 3. The drybulb temperature in the ice arena was to be controlled as well or superior than the previous temperature control in the ice arena. 4. The quality of the ice from the ice making plant could not be negatively impacted in any way. 5. Save as much energy as possible within the realms of a reasonable ROI and affordable first cost.

The combined energy savings of all of the energy reduction solutions and water savings solutions totaled just over $350,000 annually.

The engineering study set energy reduction goals for the ice plant heat recovery and desiccant air handlers of the following: Steam reduced from 18,969 mmbtu to 3,133 mmbtu. Chilled water consumption – no reductions. Local electric consumption increased from 4,182,415 kWhr to 5,236,163 kWhr. Natural gas consumption – no reduction. Local water consumption from 7,754 ccf to 5,899 ccf. Total energy reduction from 43,226 mmbtu to 31,053 mmbtu.

The engineering study set energy reduction goals for the locker room energy recovery unit at 1238 mmbtu reduction for heating and 120,481 ton-hrs for cooling.

A second locker room ERU was also studied but the first cost exceeded the amount of funds available for the project and was further not feasible due to the location of an existing chiller, emergency generator, transformer and TV truck parking needs.

We project this conversion will help further progress our institutional carbon reduction goals. Overtime, we will be able to calculate and determine carbon reductions from this particular conversion project.

The larger project was implemented by hiring an AE to conduct a study and develop design documents within the state of Ohio required contracting regulations. The AE performed a study showing the energy savings options, first costs and return on investment. A CMR (construction manager) was hired to execute the work. The CMR proposed bringing in a design assist HVAC subcontractor to assist with field work, estimating, constructability, equipment selections and schedule. The University also hired a commissioning firm with experience with ice arenas and ice plants to assist with commissioning the new equipment and systems. The firms listed were all managed by a Project Manager within Miami University who regularly manages construction and capital projects. The project was funded by the CR&R funds from the Goggin Ice Center.

The project cost was part of a larger project. As such, there were some shared costs which helped keep all the project costs low. Services such as contractor general conditions, staffing, tools, equipment could be shared. These costs were estimated and split to the different financing sources of the greater project. The project costs for the Goggin were $3,250,000 which included all AE fees, contractor costs, permits, local administration. The Goggin had built up their CR&R over the years and used that money to pay for the project. The Goggin also opted to provide temporary air handlers to serve there 2 ice pads during the construction period so that the facility did not encounter a lengthy down time; this added additional cost to the facility at $125,000. There are no recurring costs as a result of the project as the maintenance staff is on-site full time at Goggin to run the ice plant and air handlers. There is now an extra chiller and ERU to maintain but it was roughly offset by eliminating steam condensate pumps and steam pressure reducing station. The building already had a hot water system, it was now a larger system thus does not require additional maintenance time.

In our experience, sizing heat recovery chillers to handle an average load allows the chiller to operate at a steady sate so that the chiller does not have to load / unload constantly or vary flow rates all of which can lead to chillers tripping.

We sized the chiller so that it handles an average load rather than trying to size for a typical peak load. The evaporative condensers then cycle to meet higher demand. This strategy has allowed the chillers to operate very reliably at a base load condition.

We had also learned from past projects that it is important to test the chiller at the factory to ensure it performs to meet the specified performance and to ensure it operates reliably. We had this test conducted at the factory and confirmed the chiller could perform as advertised.