Simply put, the UL 710 Standard for Safety Exhaust Hoods for Commercial Cooking Equipment criteria is a fire safety test and the ASTM F1704 Standard Test Method for Capture and Containment Performance of Commercial Kitchen Exhaust Ventilation Systems is a performance based test to determine the capture and containment threshold for any given hood under a prescribed cooking line up.
The UL 710 test, which can be performed by any certified listing agency, the most notable are Underwriters Laboratories (UL) and Intertek Labs (ETL). The criteria are primarily twofold, fire safety, adherence to the requirements of NFPA 96 (National Fire Protection Association, Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations) and establishing minimum exhaust levels for a specific cooking duty, (light, medium, heavy and extra heavy duty).
The performance aspect of UL 710 is the determination of the removal of visible cooking vapors under test conditions which consists of a single appliance on the end of a hood. If the inspector determines the exhaust levels were sufficient to remove visible vapors under the given load, then the exhaust hood passes at the minimum airflow achieved. It is important to note that UL indicates that minimum exhaust volumes needed in real life conditions may be higher than the minimum for full capture and containment. This is because only a single appliance is tested, there are no people walking in front of the hood during the testing, and the tests are conducted in a draft-free space therefore the testing does not represent a real kitchen environment.
The aspect of the UL 710 Standard that verifies NFPA 96 compliance centers on hood construction, clearances and overhang requirements. Based on test outcomes, the levels achieved for the above become part of the file for that hood and must be adhered to for the hood construction and installation related requirements. It would vary for different manufacturers.
ASTM F1704 Standard Test Method for Capture and Containment Performance of Commercial Kitchen Exhaust Ventilation Systems
The ASTM F1704 Standard Test was developed to determine full capture and containment of not only visible contaminants, but the entire convective load generated by the appliances. In this way, different manufacturers offerings could be compared against the same appliance line up to provide a relative efficiency for a given load.
ASTM F1704 Standard has two standard challenges referenced in the appendices: one for canopy hoods and another for backshelf/proximity hoods.
Appendix X1 specifies the standard appliance line challenge for canopy hoods and the cooking lineup from the appendix is shown in Table X1.3 below.
- The fryers have an input of 80,000 Btu/h each vat (160,000 Btu/h per fryer)
- The full size convection ovens have an input rating of 12.1 kW
- The 3-ft gas broilers have a nameplate rating of 96,000 Btu/h
The standard canopy hood is defined as 10 ft wide by 24 in. high by 54 in. deep with a single collar sized for 18 in. wide by 12 in. deep.
The standard allows other deviations to be tested and reported.
Appendix X2 specifies a test method for a backshelf/proximity hood with a standard appliance line challenge and is presented in Table X2.3 from the standard.
The fryers and charbroiler are the same as with the canopy hood test but what is added is a gas griddle with an input rating of 96,000 Btu/h.
The hood specification for this test consists of backshelf hoods measuring from 34 to 54 inches in length to cover the test matrix in Table X2.3.
Several hood manufacturers tested canopy hoods with an expanded appliance lineup for a particular restaurant chain. As time went on, manufacturers tweaked the testing improve performance of hoods for a particular restaurant chain . Modifications included increasing the hood heights and using side skirts and rear seals. In some cases multiple exhaust collars or elongated exhaust collars were used to improve performance. The results did show an improvement in performance across the industry, but It’s important to note that those additions (increased height, use of side curtains and rear seals) that were used to improve performance also end up on the actual installation to achieve results comparable to the test.
Looking for more articles on Code Issues and Updates? What are the standards for hood overhang to specific cooking equipment? Is it based on UL Listings of the hood?