February 13, 2025
From the 2024 UPC Illustrated Training Manual, Chapter 6 – WATER SUPPLY AND DISTRIBUTION
603.5.22 Chemical Dispensers. The water supply to chemical dispensers shall be protected against backflow by one of the following:
(1) The chemical dispenser shall comply with ANSI/CAN/ASSE/IAPMO 1055. Where an installation involves a water source coming from a faucet with an integrated vacuum breaker device, a pressure bleed device conforming to IAPMO PS 104 shall be used to protect the vacuum breaker device.
(2) Water supply shall be protected by one of the following methods:
(a) Air gap
(b) Atmospheric vacuum breaker (AVB)
(c) Pressure vacuum breaker backflow prevention assembly (PVB)
(d) Spill-resistant pressure vacuum breaker (SVB)
(e) Reduced-pressure principle backflow prevention assembly (RP)
ASSE 1055 is Performance Requirements for Chemical Dispensing Systems with Integral Backflow Protection. Devices must be laboratory tested for a number of possible situations including: hydrostatic pressure, backpressure and backsiphonage. When connected to a dedicated water supply the dispenser has the necessary protection built in and no extra protection is required.
The water supply to an ASSE 1055 chemical dispenser may be from a faucet equipped with an atmospheric vacuum breaker (AVB) as long as the installation has continuous water flow when the faucet is open.
From the 2024 UMC Illustrated Training Manual, Chapter 5 – EXHAUST SYSTEMS
504.4.3.1 Exhaust Ducts for Type 2 Clothes Dryers. Exhaust ducts for Type 2 clothes dryers shall comply with the following:
(1) Exhaust ducts for Type 2 clothes dryers shall comply with Section 504.4. [NFPA 54:10.4.6.1]
(2) Exhaust ducts for Type 2 clothes dryers shall be constructed of sheet metal or other noncombustible material. Such ducts shall be equivalent in strength and corrosion resistance to ducts made of galvanized sheet steel not less than 0.0195 of an inch (0.4953 mm) thick. [NFPA 54:10.4.6.2]
(3) Type 2 clothes dryers shall be equipped or installed with lint-controlling means. [NFPA 54:10.4.6.3]
(4) Where ducts pass through walls, floors, or partitions, the space around the duct shall be sealed with noncombustible material. [NFPA 54:10.4.6.4]
(5) Multiple installations of Type 2 clothes dryers shall be made in a manner to prevent adverse operation due to back pressures that might be created in the exhaust systems. [NFPA 54:10.4.6.5] The exhaust fan shall operate continuously or shall be interlocked to exhaust air where a clothes dryer is in operation.
Exhaust fans shall operate continuously or shall be interlocked with the clothes dryer to prevent the clothes dryer from starting in case of a fan failure. If a fan is not operating, an accumulation of lint can occur in the exhaust duct and put the occupants at risk due to the potential fire hazard.
A Type 2 dryer duct system is to be listed and the installation of dryer exhaust ducts serving Type 2 clothes dryers also has to comply with the appliance manufacturer’s installation instructions. If allowed by the manufacturers listing, Table 303.10.1 of the UMC may be used for reduced clearances to combustibles of Type 2 dryer duct.
There have been instances where laundry facilities have problems with make-up air. While UMC section 504.4.1 (2) requires a minimum free area opening of 1 sq.in. for each 1,000 BTU per hour, some manufacturers require even larger net free opining area.
(This is not to be considered the official position of IAPMO, nor is it an official interpretation of the Codes.)
IAPMO
IAPMO develops and publishes the Uniform Plumbing Code®,the most widely recognized code of practice used by the plumbing industry worldwide; Uniform Mechanical Code®; Uniform Swimming Pool, Spa and Hot Tub Code®; and Uniform Solar Energy, Hydronics and Geothermal Code™ — the only plumbing, mechanical, solar energy and swimming pool codes designated by ANSI as American National Standards — and the Water Efficiency Standard (WE-Stand)™. IAPMO works with government, contractors, labor force, and manufacturers to produce product standards, technical manuals, personnel certification/educational programs and additional resources in order to meet the ever-evolving demands of the industry in protecting public health and safety.
Last modified: February 13, 2025