Top Crop Manager

Humidity solution for any warehouse

Few growers would suggest there is a perfect solution for controlling humidity in large storage facilities, but of the available options, DryFog might be the easiest to install.

April 30, 2009  By Rosalie I. Tennison

The simplicity of the DryFog system is evident at first glance: it requires only compressed air and a water line.

Photo courtesy of George Burkholder, GRB Technologies.  

Few growers would suggest there is a perfect solution for controlling humidity in large storage facilities, but of the available options, DryFog might be the easiest to install. Most humidification systems need to be installed when the warehouse is constructed and spinner systems are not always accurate. DryFog claims to be quick to install and to offer the finest droplet size available. “DryFog is very simple to install, basically you take it out of the box and put it on the wall,” says George Burkholder of GRB Technologies in Mitchell, Ontario. “The system hangs on the wall and you hook an air line and a water line to it, add some electricity and away it goes!”

An air compressor pushes the water through nozzles breaking it down into a fine mist of 4.2 micron diameter droplets. The smaller droplet size minimizes the amount of moisture that can collect in storage. The heavier the droplet the quicker it will fall on the stored crop or on the floor. The size of the water particles means the mist will drift with less moisture actually landing on the potatoes. “This is as good as any system for breaking water into small particles,” says Bert Webster of Mid-Isle Farms, Prince Edward Island. Webster has DryFog installed in two storage facilities of 15-million pounds each. “It is more expensive to run and maintain because of the size of air compressor needed and the energy to run it, but it is easy to install and can be put into any storage easily.”

Given the value of a potato crop, the option of adding an antimicrobial agent to the DryFog system enhances its overall usefulness.

Webster produces potatoes for table stock, and he says the cooler temperature needed to keep his crop at optimum freshness has caused the nozzles in the DryFog system to freeze. “If the temperature is cold and you are running your storage at 38 degrees F (three degrees C),” he explains, “there will be some nozzle freezing.” He says he does not think this is a problem for growers storing potatoes for processing because the temperature needs to be a few degrees higher. He also has an idea of how to solve the problem, he is dealing with the manufacturer to find a suitable solution.

The DryFog humidity system can also be used to deliver disease control. Combining the technology with an anti-microbial product allows for disease protection and humidity in one uniform application. “It works well to disperse chlorine dioxide or peroxygen solutions,” Burkholder explains.

The value of the DryFog system with its misting technology is that humidity can be maintained. “You need the humidity to remain above 95 per cent and then you will get very little shrink,” Burkholder continues. “If the pile of potatoes shrinks by even five per cent, a lot of money will be lost as your weight is reduced.”

Burkholder says a basic DryFog system will cost between $3000 and $3500, but that price does not include the air compressor required to run it. Considering Webster’s experience, the additional cost for a compressor will largely depend on the size of storage for which it is needed.
Since its introduction to Canada a few years ago, the DryFog manufacturer has improved the system. Originally designed with individual nozzles, the newer ES100 model is more self-contained and easier to install. When compared to other systems, there is no retrofitting of existing storage required and with an air compressor matched to the size of the storage, DryFog can be installed and running within a day. “Besides the freezing aspect, we have not had other issues with the system,” Webster comments.

For growers who need to improve their humidification system or who are retrofitting an older storage facility, DryFog is an easy solution. It is also a good choice for new storage as no space has to be allotted for additional humidification equipment. Customizable controls allow for around the clock automated operation, but occasional monitoring of storage is always recommended. With DryFog, growers get fine mist protection of a valuable crop.


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