Multi-section homes with ductwork in more than one section require crossover connections to complete the duct system of the home. All ductwork connections, including duct collars, must be sealed to prevent air leakage. Galvanized metal straps or tape and mastics listed to UL 181A (incorporated by reference, see § 3285.4), for closure systems with rigid air ducts and connectors, or UL 181B (incorporated by reference, see § 3285.4), for closure systems with flexible air ducts and connectors, must be used around the duct collar and secured tightly to make all connections.
If metal straps are used, they must be secured with galvanized sheet metal screws.
Metal ducts must be fastened to the collar with a minimum of three galvanized sheet metal screws equally spaced around the collar.
Air conditioning or heating ducts must be installed in accordance with applicable requirements of the duct manufacturer installation instructions.
The duct must be suspended or supported above the ground by straps or other means that are spaced at a maximum distance not to exceed 4′-0″ or as otherwise permitted by the installation instructions. When straps are used to support a flexible type duct, the straps must be at least 1/2″ wider than the spacing of the metal spirals encasing the duct. The ducts must be installed such that the straps cannot slip between any two spirals and arranged under the floor to prevent compression or kinking in any location, as shown in Figures A and B to this section. In-floor crossover ducts are permitted, in accordance with § 3285.606(g).
Crossover ducts outside the thermal envelope must be insulated with materials that conform to designs consistent with part 3280, subpart F of this chapter.
In-floor or ceiling crossover duct connections must be installed and sealed to prevent air leakage.
1. This system is typically used when a crossover duct has not been built into the floor and the furnace is outside the I-Beam. With this type of installation, it is necessary for two flexible ducts to be installed.
2. The crossover duct must be listed for exterior use.
1. This system is typically used when a crossover duct has not been built into the floor and the furnace is situated directly over the main duct in one section of the home. A single flexible duct is then used to connect the two sections to each other.
2. The crossover duct must be listed for exterior use.
Copyright ©2024 LegalFix. All rights reserved. LegalFix is not a law firm, is not licensed to practice law, and does not provide legal advice, services, or representation. The information on this website is an overview of the legal plans you can purchase—or that may be provided by your employer as an employee benefit or by your credit union or other membership group as a membership benefit.
LegalFix provides its members with easy access to affordable legal services through a network of independent law firms. LegalFix, its corporate entity, and its officers, directors, employees, agents, and contractors do not provide legal advice, services, or representation—directly or indirectly.
The articles and information on the site are not legal advice and should not be relied upon—they are for information purposes only. You should become a LegalFix member to get legal services from one of our network law firms.
You should not disclose confidential or potentially incriminating information to LegalFix—you should only communicate such information to your network law firm.
The benefits and legal services described in the LegalFix legal plans are not always available in all states or with all plans. See the legal plan Benefit Overview and the more comprehensive legal plan contract during checkout for coverage details in your state.
Use of this website, the purchase of legal plans, and access to the LegalFix networks of law firms are subject to the LegalFix Terms of Service and Privacy Policy.