4.5. SR 04-20-1998 - Laserfiche WebLink

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ELK RIVER ARENA ELK RIVER, MINNESOTA APRIL 8, 1998 FEASABILITY STUDY SYSTEM RECOMMENDATIONS We recommend that significant changes be considered for the design of the ventilation system. The existing system is creating problems that will greatly reduce the life of the building. Continued use of the facility during warm summer months will result in deterioration of the roof deck and other exposed metal surfaces, deterioration of the building electrical components, possible deterioration of sheet rock walls and increased liability due to the wet floor surfaces. We strongly recommend that a desiccant based dehumidification system be considered for the facility. Desiccant based dehumidification systems use a material that has a high affinity for water to absorb the moisture from the air. Systems typically consist of a large air handler with a desiccant wheel installed in the air stream. The moist ai~ is forced through the desiccant wheel. Moisture is removed from the air stream and collected by the desiccant wheel. The wheel continually rotates with a portion of the wheel moving out of the arena air stream. The moisture is then forced off of the wheel into the atmosphere by a heating process. The dry portion of the wheel then rotates back into the moist air stream to continue the dehumidification process. The units are particularly suited for ice arena applications. We have installed desiccant based dehumidification systems in numerous facilities in the Twin City area and around the country with great success. The systems have the following advantages: 1. The desiccant based dehumidification systems are capable of drying the air to a much lower moisture content than refrigeration based systems. 2. The ventilation air is typically dehumidified before it is introduced into the arena. This removes the single largest source of moisture from the facility. 3. The amount of ventilation air introduced into the facility can be varied with the occupant load in the building. This reduces the overall dehumidification load and energy consumption of the facility. 4. The systems use natural gas or other sources of heat to regenerate the wheel. This reduces the electrical demand on the facility. The need for dehumidification normally is coincident with the highest energy demand on the ice plant. Switching from an electrically driven, refrigeration based dehumidification system, to a desiccant based system which uses natural gas as it's energy source will remove a portion of the electrical demand charges from the facility. 5. The Gas Company providing gas to the facility is very interested in the use of desiccant based systems. The systems consume natural gas during the summer when the gas companies have a small total demand, and they typically do not operate on cold winter days when the gas companies have their highest demand. The gas companies offer rebates to offset the first cost of the system. They also offer rebates to offset the engineering costs for the design of the system. We recommend that a desiccant based dehumidifier with a total air flow capacity of 12,000 f¢/hr be provided for the arena. The system should have the capacity to remove approximately 420 lbs/hr of moisture from the air. This system would be capable of introducing enough outside air into the facility to ventilate the arena during a resurfacing operation and also provide adequate ventilation for the occupants of the building during a summer time event. The proposed ventilation rate is less than the existing system which will lower the dehumidification requirements for the building. 600 lbs/hr are required for the existing ventilation system. NELSON-RUDIE & ASSOCIATES, INC. Page 6