Case study

A former HVAC technician, Schmitzer also has growing experience from his 10 years as a patient/caregiver career under the Michigan Medical Marijuana Program that allows licensees to grow up to 72 plants for patient use. His experience led to installing environmental controls systems that combine conventional split system HVAC air handlers, fabric ductwork for uniform air distribution, UV-C disinfection lamps, carbon media to adsorb volatile organic compounds (VOC), HEPA filters and other tricks Schmitzer learned from both the HVAC and cannabis industries.

Solution

Condensation is a grower’s enemy. Unlike metal systems, permeable fabric ducts eliminate condensation concerns in grow rooms. Dry conditioned air pushes through the fabric to prevent the humid ambient from contacting the duct’s surface,

When Schmitzer realized ductwork was necessary, fabric was the obvious choice. “I know that fabric ducting is the way to go, because metal duct has too much condensation potential,” he said.

The HVAC design features more than 700 linear feet of 16-inch-diameter fabric ductwork for three 1,600-square-foot flower rooms and a small nursery. There’s also a one-of-a-kind, fabric dispersion plenum for the dry/cure room that Schmitzer designed with FabricAir factory engineers.

Results

The linear OriFlow arrays and surface permeability create uniform dispersion throughout the space. This results in shorter mechanical system run times to satisfy temperature set points and to reduce energy costs compared to metal duct. Fabric duct was proven to be approximately 25% more efficient versus metal duct/register systems, according to a fabric/metal duct comparison conducted by the Iowa State University’s mechanical engineering department.

The proof that HVAC design can positively affect cannabis profits is in High Mountain’s impressive harvest statistics of two-lbs/1,000-watt light (over 100-lbs/50-light room), of high THC content flower, which is well above average yields by Michigan standards.