Ductmate offers a comprehensive range of products designed for HVAC duct construction, access solutions, and support systems. This guide compiles essential installation instructions and technical specifications from Ductmate’s official documentation to assist professionals and DIY enthusiasts in ensuring accurate and compliant installation. The content is organized to cover key components such as flange calculations, access doors, support systems, and sealing techniques, all while adhering to industry standards like SMACNA and LEED requirements.
Installation of Ductmate Flange Systems
The Ductmate flange system is designed to ensure airtight and durable connections in HVAC ducts. Proper installation involves precise calculation of the required flange length and understanding the appropriate number of corners, cleats, and gaskets.
Flange Calculation Formula
To determine the total lineal feet of flange needed for a given duct line, use the following formula:
(Width of Duct in Inches + Height of Duct in Inches) / 3 = Total Lineal Feet of Flange Needed per Joint.
Multiply this result by the number of joints needed, which is typically one more than the number of duct sections being fabricated.
For example, a duct size of 40” x 30” would require the following:
- Feet per joint: (40 + 30) / 3 = 23.33 lineal feet per joint
- Number of sections: 5
- Number of joints: 6
- Total flange needed: 23.33 x 6 = 139.98 lineal feet (rounded up to 140 lineal feet)
Additional Components
- Corners: One corner for every 3 lineal feet of flange
- Cleat: One 6” piece of cleat for every 4 lineal feet of flange
- Gasket: One lineal foot of gasket for every 2 lineal feet of flange
Rooftop Installation Considerations
For rooftop applications, Ductmate recommends using a 10’ continuous metal cleat on the top duct flange instead of a 6” cleat to prevent water accumulation on the gasket. It is also important to avoid using PVC (plastic) cleat in outdoor environments.
Access Door Installation and Specifications
Ductmate provides various access door systems, including insulated, square framed, and round connector options, each with specific installation requirements and performance characteristics.
Insulated Access Doors
- Insulated round and rectangular Sandwich Access Doors: Rated R-value of 2.1
- Square Framed Access Doors: Rated R-value of 4.2
- F2 Access Door: Features a ceramic fiber gasket suitable for temperatures up to 2300°F, meeting NFPA96 standards
Round Connector Systems
Ductmate’s round connector systems support up to a 12 gauge longitudinal seam. The system offers two profiles:
- Small Profile: Available from 8” to 30” with 22 gauge flanges and 20 gauge closure band
- Large Profile: Available from 30” to 72” with 20 gauge flanges and 18 gauge closure band
Each profile has specific gauge limitations:
- Small Profile: Not suitable for gauges heavier than 20 gauge or lighter than 28 gauge
- Large Profile: Not suitable for gauges heavier than 16 gauge or lighter than 28 gauge
For grease duct applications, Ductmate offers a UL1978 Listed Ultimate Round Access Door.
Measuring for Round Ducts
To determine the diameter of a round duct, use the formula:
Diameter = Circumference / π (3.1416).
Use a flexible tape measure to obtain the circumference.
Support and Suspension Systems
Ductmate’s support systems are engineered to meet structural and environmental requirements, ensuring safe and efficient installation in various environments.
Cable Shark System
The Cable Shark is a hanger system tested and approved by SMACNA per Chapter 4 of the HVAC Duct Construction Standards. It is suitable for both spiral and rectangular ductwork.
- Weight Load Capacity:
- CS125: 125 pounds
- CS250: 250 pounds
- Installation Restrictions:
- Cannot be used outdoors or in high-humidity environments such as indoor pools
- Cannot be reused after initial installation; new mechanisms and cable must be used for each installation
The system uses aircraft-quality cable that is specifically designed for each model. The serrated jaw assemblies and bore dimensions are engineered to match the cable diameter for consistent performance.
- Cable Cutting: A Ductmate cable-cutting tool is recommended to ensure a clean, precise cut. Other tools like tin snips or diagonal cutters may fray the cable end, affecting installation.
- Pre-Cut Lengths: Available in 5’, 10’, 15’, and 20’ standard lengths; custom lengths are also available upon request
Hurricane Air Brace
For outdoor installations, UV-resistant Hypalon-coated woven fiberglass fabric is recommended. Ductmate’s Hurricane Air Brace does not require a Notice of Acceptance (NOA) under the Florida Building Code, as it is based on engineering calculations. Contractors are responsible for submitting the design to the Building Official with the engineer’s seal.
Slip & Drive
Ductmate’s Hemmed S Slip and Drive Slip are available in various sizes:
- Hemmed S Slip: 6” through 24” in 2” increments (straight end only)
- Drive Slip: 4” through 26” in 2” increments
Quick Sleeve Installation for Pipe Access
The Quick Sleeve system allows access to the interior of round ducts for cleaning or inspection when standard access doors are impractical. The installation involves the following steps:
- Remove one-foot section of pipe where access is needed
- Install a Quick Sleeve on each open end of the pipe
- Reinsert the one-foot section of pipe, sliding each Quick Sleeve over the cut openings and tightening the bolts to create an airtight seal
- For access: Loosen the bolts on the Quick Sleeves, slide them back, and remove the one-foot pipe section
- To re-install: Follow the same steps in reverse
Sealing and Adhesive Considerations
Ductmate provides sealants and adhesives that meet LEED EQ 4.1 standards for Low-Emitting Materials. These products are suitable for both interior and exposed ductwork applications.
Sealing from Inside or Outside
The joint can be sealed from either the inside or the outside of the duct. If the duct is exposed, sealing from the inside is preferred for aesthetic reasons.
Disposal Guidelines
Ductmate recommends using all available sealant on the duct to minimize waste. If the product has cured, it can be disposed of in regular trash. For large quantities, it can be mixed with shredded paper or cardboard to accelerate curing. Always consult local regulations for disposal compliance.
Application Tools
PROseal Spray can be applied using most commercial-grade paint sprayers, such as the Graco 390 Airless Electric Sprayer, which is suitable for entry-level applications. Ensure the sprayer pump supports a minimum .021” tip size. Always follow the manufacturer’s instructions for the spray equipment used.
Vane and Rail Installation
Ductmate’s Vane and Rail system is used to improve airflow in mitered elbows by reducing turbulence. Installation involves calculating the number of vanes and the total length of rail needed.
Vane Spacing and Number
- Determine rail length: Measure the distance across the throat of the elbow in inches
- Divide by tab spacing:
- 2” PROrail: 2-1/8” spacing
- 4” PROrail: 3-1/4” spacing
- Calculate number of vanes: Divide the rail length by the tab spacing
- Determine total vane height: Multiply the number of vanes by the height of the vane
Vane Sizing and Performance
A general rule of thumb is to use 2” vanes when the elbow can accommodate at least 4 vanes across the diagonal. If less than 4 vanes can fit, consider using a radius elbow to minimize turbulence and maintain airflow efficiency.
Fire and Temperature Considerations
Ductmate does not manufacture fire-rated access doors. Fire-rated doors are typically used in fire-rated walls and ceilings to maintain fire resistance while providing access. For high-temperature applications, the F2 access door is recommended due to its ceramic fiber gasket, which can withstand temperatures up to 2300°F and complies with NFPA96 standards.
Conclusion
Ductmate’s installation instructions and technical specifications are designed to ensure safe, efficient, and code-compliant HVAC system construction. From flange calculations and access door installation to support systems and sealing techniques, each component plays a critical role in system performance. By following the guidelines provided in the official documentation, professionals and DIY enthusiasts can achieve optimal results while adhering to industry standards.