507DR814 – 14” Start Collar w/ Damper

507DR814 14 Inch Start Collar with Damper is an HVAC air-distribution fitting designed to connect a compatible plenum or ductboard surface to 14-inch round ductwork. Its integrated damper provides a convenient way to adjust the airflow moving through the connected duct branch during system setup and balancing.

This start collar is identified as model 507DR814 and features galvanized steel construction. Before ordering, verify the required duct diameter, mounting surface, available installation space, and airflow requirements of the complete HVAC system.

507DR814 14 Inch Start Collar with Damper Features

The 507DR814 14 Inch Start Collar with Damper combines a round duct connection and an airflow-control component in one fitting. It creates a starting point for a compatible 14-inch duct branch while allowing airflow through the branch to be adjusted.

• Model number: 507DR814
• Nominal connection diameter: 14 inches
• Durable galvanized steel construction
• Integrated damper for airflow adjustment
• Connects compatible round HVAC ductwork
• Suitable for compatible air-distribution systems
• Useful for new installations and replacements
• Professional installation recommended

The collar forms the transition between the primary air-distribution component and the round branch duct. Correct positioning, fastening, and sealing help create a stable connection and reduce unwanted air leakage around the opening.

Integrated Airflow Damper

The damper included with the 507DR814 14 Inch Start Collar with Damper allows airflow through the connected branch to be adjusted. This feature can support system balancing when different rooms or areas require different quantities of supply or return air.

A damper should not be used to compensate for incorrectly sized ductwork. The branch duct, collar, register, grille, and other fittings must be selected according to the required airflow and static-pressure limitations of the HVAC system.

Damper position should be adjusted carefully during system startup or balancing. Excessive restriction can increase static pressure, reduce airflow, create unwanted operating noise, and negatively affect comfort in the connected area.

After adjusting the damper, confirm that air continues to move properly through the duct branch. Keep the adjustment mechanism accessible whenever possible so future inspections and airflow corrections can be completed without dismantling the duct system.

Galvanized Steel Construction

The 507DR814 14 Inch Start Collar with Damper uses galvanized steel to provide a durable round connection for compatible HVAC ductwork. The galvanized finish helps protect the metal during normal handling, installation, and operation.

Inspect the fitting before installation. Do not install a collar that is severely bent, damaged, corroded, or unable to maintain a secure round connection. Minor shipping deformation should be corrected carefully without damaging the damper mechanism.

The mounting surface must be strong enough to support the collar and connected ductwork. Do not install the fitting on wet, deteriorated, damaged, or structurally weak material.

Installing the 507DR814 Start Collar

Before installing the 507DR814 14 Inch Start Collar with Damper, verify the planned location and make sure there is adequate clearance for the fitting, damper mechanism, connected ductwork, insulation, fasteners, and sealing materials.

Mark the opening carefully using the dimensions required by the fitting. Cut the mounting surface with tools appropriate for the material. Remove sharp edges, loose fibers, metal fragments, and other debris from the installation area.

Position the collar evenly in the prepared opening. Secure it using approved fastening methods suitable for the mounting surface. The completed connection should remain stable without deforming the collar or damaging the surrounding material.

Seal the complete perimeter using HVAC-approved mastic, sealant, or listed tape compatible with the mounting surface. An airtight connection helps reduce conditioned-air loss and limits unwanted air from entering a return-air system.

Follow applicable mechanical codes and approved HVAC installation practices. The exact fastening and sealing method may vary according to the mounting material, air-distribution system, and local requirements.

Connecting Flexible Round Duct

When connecting flexible duct to the 507DR814 14 Inch Start Collar with Damper, pull the flexible inner core completely over the round collar. Secure the core with an approved clamp, band, or fastening method and seal the inner connection.

Pull the insulation over the completed connection without leaving exposed gaps. Secure and seal the exterior vapor barrier around the collar according to the flexible duct manufacturer’s installation requirements.

Flexible duct should follow a smooth and direct route. Avoid sharp bends, excessive compression, twisting, unnecessary length, and unsupported sections because these conditions can increase resistance and reduce airflow through the 14-inch branch.

Connecting Rigid Round Duct

When connecting rigid round duct, align the duct and collar properly before securing the components. Use approved mechanical fasteners and seal the full circumference of the joint with HVAC-approved mastic, sealant, or listed tape.

Rigid duct sections should be independently supported. The start collar and mounting surface should not carry the complete weight of long ducts, heavy transitions, fittings, or other air-distribution components.

Inspect the inside of the connection before operating the system. Confirm that screws, duct edges, or excess sealant do not interfere with the operation of the integrated damper.

Airflow and Duct Sizing

A 14-inch duct connection is not suitable for every HVAC application. Required duct diameter depends on airflow demand, duct length, fitting resistance, number of elbows, blower performance, static pressure, and the requirements of the connected space.

The 507DR814 14 Inch Start Collar with Damper should be selected as part of a complete air-distribution design. Do not determine compatibility only by comparing the collar diameter with existing ductwork.

A qualified HVAC professional can calculate the required airflow and determine whether a 14-inch branch is appropriate. The technician can also adjust the damper while measuring airflow and system static pressure.

Inspection and Maintenance

Inspect the fitting during routine HVAC maintenance. Check for loose connections, damage to the mounting surface, deteriorated sealant, air leakage, unusual vibration, corrosion, and obstructions around the damper.

Whistling, rattling, or excessive airflow noise may indicate an air leak, restriction, incorrect damper position, loose fitting, or duct-sizing problem. Evaluate the complete branch before making additional adjustments.

Professional Installation Recommended

Professional installation of the 507DR814 14 Inch Start Collar with Damper is recommended. Correct placement, fastening, sealing, support, duct sizing, and damper adjustment are essential for dependable airflow and system performance.

This product includes the start collar and integrated damper. Flexible duct, rigid duct, clamps, fasteners, sealants, insulation, supports, and other installation materials may be sold separately. Confirm all required components before ordering.

Browse additional fittings and air-distribution products in the Xpress Supply Ducting & Venting category. For general heating, cooling, and energy-efficiency information, visit the U.S. Department of Energy Energy Saver.