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Informational Report on the Larson Ice Center Ice System Replacement.
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Summary:
Ubl Design Group, in collaboration with the Parks, Recreation and Forestry Department, wishes to provide information to the City Council pertaining to the need and feasibility of options for replacement of the ice system at the Larson Ice Center.
Introduction:
The primary focus is to evaluate the ice system replacement options along with other factors pertaining specifically to Larson Ice Center that will influence the recommended choice of system to move forward with. Factors include: building usage, constructability, building operations, phasing strategies, scheduling, financing and long-term sustainability.
Building Background -
Larson Ice Center opened in 2002 and consists of two regulation sized ice sheets and a holding barn. The building square footage is approximately 75,600 SF. The current ice system type is an R22-Indirect/Glycol system. The life expectancy of this type of system is approximately 20-25 years. Due to a handful of concerns, the Larson Ice Center ice system is failing and outside professional recommendations state that the ice system and ice rink floors be replaced as soon as feasibly possible.
Groundwater Mitigation -
The consultant has identified that wet and saturated soils exist just below the rink floors, which has led to the failure of the steel piping system. It is believed that the heave in the Red Rink floor reflects the wet soils under the rink floor freezing during the ice season. The consultant recommends installing a water mitigation system under the new rink floors and upgrading water mitigation issues on the entire site including the parking lots and roof drainage.
Ice System -
Based on the assessment, three primary issues need to be evaluated in determining a replacement system.
1. The heat exchanger has failed and needs replacement. The cost for this replacement is between $44,000 to $50,000. Note: replacing the current heat exchanger alone will not solve wet and frozen soil conditions, as the pipes are leaking under the rink floors.
2. The roof top condenser units working in collaboration with the ice system have failed, been repaired multiple times, and have reached the end of their life cycle. The cost for replacement of the condensers will cost between $165,000 and $175,000.
3. The refrigerant R22 that is utilized in our current system will no longer be produced in its virgin form after January 1, 2020 due to hazardous EPA concerns. This will cause unknown consequences for users relying on R22 as a refrigerant source. An educated guess is that R22 will become increasingly expensive for any leaks that require R22 replacement. The positive, as this pertains specifically to Larson Ice Center, is that the current R22 system, regardless of ice system issues, will need replacing at some point in the future and this is an opportune time to do so.
Report Conclusion -
1. Groundwater under the rink floors and around the building has contributed to the concrete floors heaving.
2. The underground heating system that protects the concrete floors from heaving has failed from a combination of leaks in the piping and a damaged heat exchanger.
3. The Red Rink concrete slab has failed beyond repair and must be replaced.
4. The Blue Rink concrete slab has minor cracking, which could be repaired, but it must be removed to access and replace the leaking underfloor heating system.
5. The ice plant operates using R22 as the primary refrigerant. R22 in its virgin form will be no longer available after January 1, 2020. There are no proven replacements for R22 that can operate the ice plant. In addition to the R22 issue the ice plant needs over $250,000 worth of upgrades and improvements to operate correctly. The life of an R22 ice plant is limited into the future based on the phasing out of R22, this could result in any repairs to an R22 system becoming obsolete in the next 2 to 5 years.
Ice System Options -
Based on the report conclusions, a new ice system is needed for Larson Ice Center. Four ice system options were looked at including 1) 507/134a system, 2) Ammonia/Glycol Indirect system, 3) CO2/Glycol Indirect system and 4) CO2 Direct system. The four systems were evaluated based on the following primary attributes:
• Ease of staging over two - three seasons
• Delivery and timeliness of manufacturing the ice plant system
• Cost of refrigerant
• Energy efficiency
• Ice quality
• Cost of maintenance
• Initial cost
• Total life cycle costs
…Recommendation
Recommendation:
Based on the consultant’s opinion and staffs review, staff recommends moving forward with replacing both rink floors, installing a rink water mitigation system, addressing overall site water mitigation options, and installing a CO2 Direct ice plant system. The recommendation is based on the timeliness and urgent need to replace the rink floors, the initial and total life cycle costs, and ice quality provided by the CO2 Direct ice plant system. It should be noted that this option requires both rink floors be replaced at the same time due to the nature of installing the CO2 Direct ice plant system. Total cost estimates for both rinks range between $3,000,000 to $3,600,000 plus additional drainage work.
Due to the urgent timeliness for scheduling, manufacturers lead timeline for manufacturing a new ice system, and the potential for a complete failure of the current R22 ice system, staff is recommending proceeding forward with this project in 2019. Staff will develop a RFP through a design build process to expedite and potentially reduce mobilization costs for this project.
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