By Peter Boileau
Chairman of the ICC Code/Technical Advisory Committee
The Code and Technical Committee has been hard at work in 2018, with 18 members addressing a wide array of issues that can potentially affect everyone in our industry. In this article we will describe two issues that have been reviewed by our group and provide our consensus opinions on how to address code compliance.
Installation of pollution control units (PCUs) in Type 1 grease exhaust systems: The use of these “air scrubbing” devices in Type 1 grease duct systems (as defined by the International Mechanical Code, Section 506) has become a popular option in lieu of traditional grease exhaust fans in this type of system. The popularity stems from several things, including the construction of mixed-use buildings that combine residential living units with restaurant spaces on street level. Developers are aware that grease odors and particulates from Type 1 systems are not conducive to happy residents in these buildings and scrubbing the air with PCUs is an excellent solution to this challenge.
When installing a PCU in these systems instead of an exhaust fan, the code requires the installation of a vibration isolation device at the duct to PCU connection (506.3.2.4). In our review there appears to be no “listed and labeled” product currently on the market that meets this code requirement, and to comply it is necessary to submit an “approved” design to the code official for review and approval prior to installation. An approved design must include flexible connection material that is rated for continuous duty at a temperature of not less than 1,500 degrees Fahrenheit. This approved design should be recommended by the manufacturer of the PCU to be installed, and the code committee suggests that this component of the PCU installation should be coordinated with the selected manufacturer and be included with manufacturer’s equipment submittals, and specified on the permit drawings if possible, to ensure that this component and therefore the entire installation clearly meets the code requirements described above.
Installation of low voltage remote powered balancing dampers: Low voltage remote powered balancing dampers are typically used in duct systems that are installed above ceilings that are high above the floor, difficult to access, or made of rigid gypsum board attached to a framing system (often called “hard”) in all types of buildings. Although expensive, powered dampers have proven more reliable and more accurate for balancing these systems when compared to linkage or cable actuated remote dampers. One issue with their installation, however, involves a potential code requirement for ceiling access doors to service the motors used with this type of damper.
The committee looked at several possible code interpretations of installing low voltage motors without ceiling access doors, which are required by code for “inspection, repair, replacement, or adjustment”. As we have probably all experienced, numerous access doors in hard or high finish ceilings are not popular with architects and building owners. The committee’s recommended solution for addressing the issue of leaving these motors inaccessible is to obtain a letter from the damper manufacturer that they are approved for installation with no access doors. This letter should be obtained from the manufacturer at the time of purchase of the dampers and presented to the on-site inspector prior to installation, avoiding after-the-fact code “interpretations” and potential ductwork and/or ceiling rework costs to address this code issue after installation is complete. ß
