Hygienic ductwork is crucial in food and beverage facilities because it provides cleanability and a way to convey filtered process-conditioned air. Other engineering firms may focus on the hygienic duct air handler rather than the entire air delivery system. To maintain sanitary standards, hygienic duct design, and fabrication are required. At Bassett Mechanical, we have the expertise and tools to meet our customer’s hygienic ductwork needs for their facility with our double-wall ductwork.


Double Wall Ductwork Curved Duct on RoofA long-time customer and food manufacturer was doing a remodel at the company’s largest volume-producing plant in North America. The project would include more than 1500 feet of ductwork.

At the beginning of the project, we were given renderings for insulated metal panels (IMP), but it was challenging to get the panels at the time, and the lead times were long. We wanted to provide the customer with an alternative solution, so we presented our double-wall ductwork. To be as transparent as possible, we made ductwork samples and showed them to the customer so they could see the type of product they were receiving. They approved our alternative solution, and we moved the project forward. We just completed a project with another refrigeration customer using the double-wall ductwork and are seeing great results.


During the process, we listened, discovered, and devised the best plan for the customer. We understood their needs and goals and familiarized ourselves with the facility.

With the assistance of our virtual design and construction team, we laser-scanned the existing building. Laser scanning improves planning as it provides the team with exact measurements. Double Wall Ductwork Model (2)We could put the entire project into a model, review it with the customer, identify collisions, and change any layouts before the project started.

The customer could see the model and determine where the access doors would go for cleanability. In addition, the customer brought in their duct cleaning subcontractor so they could review the placement of the access doors before any onsite work was completed.

Once the customer approved the models and schedule, we continued with the pre-fabrication in our manufacturing facility and then to on-site installation. We worked with the general contractor and customer to determine the appropriate schedule for everyone’s needs. The project had several systems, and depending on the system the customer needed, we could get that system completed quickly, meet the construction schedule, and move on to the next system.

VDC allows us to do most of the prefabrication work in our manufacturing facility and minimal work on the job site, helping to reduce costs, minimize safety risks, and keep the project on schedule.

Double Wall Ductwork Food Process Facility copyDouble Wall Ductwork Model



Food safety and sanitary standards require hygienic duct design and fabrication that eliminates “catch points” that could become points for bacterial growth and microorganisms. Our team knew our double-wall ductwork solution would best fit this customer’s needs and produce the best results.

Our double-wall duct is created with our 2T or 3T weld finish. It can include caulked flanges or welded joints, a 304SST 16-gauge inner duct, and an outer jacket that can be galvanized or stainless steel with varying degrees of section finish options.

Double Wall Ductwork Worker on Roof While many options are available for double-wall ductwork, Bassett prefers round ductwork to eliminate the risk of contaminants, better watersheds, and no snow load. In addition, because we foam spray insulation, the ductwork has no gaps or voids to help with efficiency.

“The customer’s plant has an alternative style of ductwork less than 100 feet away from our double-wall ductwork. After installation and completion of the project, we received feedback that ours was more robust, the outer layer was thicker, and the duct was more visually appealing,” said Steve B, Metal Fabrication Project Manager.

During a project, we want to look ahead and understand the benefits the customer will receive with the product. Below are some benefits the customer is seeing with the double-wall ductwork.

Hygienic Environment:

Maintaining a hygienic environment is paramount in food and beverage facilities to prevent contamination and ensure product quality. Double-wall ductwork offers advantages in terms of cleanliness and sanitation. The separation between the inner and outer walls prevents the accumulation of dust, debris, and microorganisms, making it easier to clean and maintain proper hygiene standards.

Energy Efficiency:

Double wall ductwork contributes to energy efficiency by reducing thermal losses or gains. Minimizing heat transfer through the ducts allows the facility to operate HVAC systems more efficiently. This helps reduce energy consumption, lower operational costs, and improve overall sustainability.

Uncompromised quality control:

Highly skilled fabricators do fabrication in a controlled, ISO-certified manufacturing facility where construction site safety hazards are eliminated. Insulation is done in a temperature-controlled manufacturing environment eliminating field-related impacts.

Consolidated project schedule:

Our ability to perform prefabrication in our 268,000 sq. ft. manufacturing facility reduces the risk of onsite delays. It maximizes the ability to produce a quality product on time and on budget. Schedule consolidation often results in cost savings for the customer.

Build Quality that Lasts:

Higher-quality duct construction can eliminate issues with field-applied insulation and compromised vapor barriers. The jacketing duct is far more durable than the light gauge field-applied jacketing systems and has shown reduced duct leakage compared to traditional commercial ducts.


Our full-service solutions for this project include metal fabrication, engineering, VDC, and industrial refrigeration and HVAC installation.


The above factors collectively contribute to the facility’s overall quality, safety, and productivity. With the additional benefits of the double-wall ductwork, we believe the customer is receiving the highest quality hygienic duct on the market.

Choosing this customized solution allows our customers to combine their unique facility and product requirements with a tailored air delivery system that puts them ahead of industry standards.

Bassett Mechanical’s breadth of capabilities is another example of our focus on Creating Customers for Life®.