Solving Humidity Problems in Recreational Ice Facilities
If you can control the humidity in your ice facility, you are one huge step toward creating ideal ice conditions. Humidity enters an ice facility through infiltration, incoming ventilation air, the opening of doors, from the kitchen, from the showers, the Zamboni bay with its snow melt pit, and through the normal respiration of the people within the building.
Following are some of the main benefits realized with the installation of a desiccant dehumidifier:
- Superior control of humidity
- Greatly improved ice conditions
- No fogging during warm weather
- Reduced moisture permeation of the facility
- Reduced maintenance costs
- Reduced operating costs of dehumidification
- Reduced operating costs of the ice plant
- Reduced molding
- Increase indoor air quality
Just as a boiling kettle deposits moisture on a cold window on a winter's day, airborne moisture in an ice facility will also deposit on cold surfaces and, of course, the coldest spot is very likely the ice surface itself. When this happens, the ice will become slow as a result of frost formation.
In addition to the aesthetic inconveniences caused by excessive humidity, there are other hidden perils that can be much more sinister in their nature. When the water vapor condenses into droplets on the ice surface, it releases a tremendous amount of heat that must be removed at the expense of operating the refrigeration equipment longer than would normally be required. Condensation can permeate your building insulation, drastically reducing its effectiveness and, of greater consequence, structural steel will start to rust and wood will start to rot, further reducing the integrity of your facility.
Luckily, with proper design, humidity can be controlled effectively and efficiently. For many years, mechanical dehumidifiers were the only game in town. The principal was based on drawing air through a refrigerated coil held at a temperature below the dew point of the air. This would cause the moisture in the air to condense on the cold coils and run off, similar to a household air conditioner. The downfall of the mechanical dehumidifiers was the fact that their effectiveness drastically falls with the lowering of the temperature in the facility. They work great when the building is warm during the initial start up period, but virtually become ineffective at temperatures much below 45 F. The ongoing cost of maintenance is also inherently high, and they were often mounted in places that made access very difficult.
For many years, desiccant dehumidifiers have been gaining favor in the recreational ice industry and now with recent models that are powered entirely by reclaimed heat from the refrigeration system they are a winner from every perspective. A desiccant dehumidifier is composed of an air handler with a fan section, a slowly rotating desiccant wheel and a regeneration section, which can get its heat from propane, natural gas or heat reclaim from the refrigeration system.
The fan section draws fresh air into the building as well as recirculating and distributing the air within the ice rink. Many studies in recent years have cited the potential for serious problems associated with indoor air quality within ice skating facilities. The desiccant dehumidifier has the added benefit of replenishing the fresh air as well, and dehumidifying it at its source before it has a chance to condense on cold surfaces.
The desiccant wheel is composed of a honeycomb structure impregnated with silica gel (the material that is in the little moisture-absorbing sachets in electronic boxes and briefcases). The moisture-laden air is passed through the slowly rotating desiccant wheel allowing the moisture to be absorbed. The humidity content in the air coming off the wheel is greatly reduced.
As humidity is being absorbed from the air passing through the slowly rotating desiccant wheel, a portion of the wheel enters the heated regeneration section. This is the section where the moisture is driven off much like the way a clothes dryer operates. The regenerated silica gel is now capable of absorbing more moisture as it rotates back into the fan section.
Although the effectiveness of the system is increased by a properly designed distribution system, ductwork is not required throughout the entire facility. A good method of distributing air is through the use of an easy-to-install fabric duct sock that is run down the center or side of the ice surface. The extremely dry air leaving the desiccant system creates a "dry hole" that literally draws moisture from all corners of the building. It is advisable to introduce a small amount of dry air above a low-e ceiling to head off any future moisture problems, which notoriously plague these installations.