April 27, 2020
Photo by Paul Wellman
With about 500,000 square feet of greenhouse production, 22,000 square feet of manufacturing space and about 10,000 square feet of processing in Santa Barbara County, Calif., the Glass House Groupfollows multiple-step processes to ensure product safety at its cultivation facility, Glass House Farms.

To provide top quality products and pass product testing, the Glass House Group uses air purification to help prevent undesirable bacteria, fungi and spores from taking hold, says founder and President Graham Farrar.

1. Identify what needs to be removed from the air and try to resolve the issue before filtering.

In cultivation, Glass House Farms tests for spores of salmonella, E. coli and Aspergillus—a mold that California regulators also test for—and uses purification to help eliminate any that may be present in the air. Some filters also can remove spores that cause plant diseases like powdery mildew and botrytis.

Cultivators who are trying to filter out fungal spores like Aspergillus must first determine the source, Farrar says. “I think the best filtration starts with reducing, mitigating, eliminating whatever it is you’re trying to filter first, and then using your filtration to remove anything that still remains.”

2. Make sure your fan is pushing the correct airflow through your filter.

Air filters should include a chart with the cubic feet per minute (CFM) of airflow they are rated for, Farrar says. Some growers push too much airflow through their filters and don’t leave enough “dwell time” for the system to filter the air, he adds.

 

3. Dehumidify air before sending it through the filter.

Humid air can clog a filter, Farrar says. One of the ways cultivators can avoid this is by dehumidifying their air before it reaches the filter..

4. Clean the filter regularly, especially in humid environments.

If relative humidity is high, cultivators should clean or replace their air filter more regularly to prevent the filter from clogging,