ZERO'S AUTOMATIC DOOR BOTTOM BOOSTS STC RATINGS IN DOOR MANUFACTURER TESTS
Tested through five million cycles, Zero International’s High Sound Automatic Door Bottom proves its worth one Sound Transmission Test at a time. In separate recent tests of acoustical assemblies commissioned by door manufacturers, Zero’s model # 369 heavy-duty mortised door bottom replaced competitor door bottoms, while perimeter gasketing and door construction remained unchanged. The results were persuasive – the STC rating of one tested assembly increased by two points, and the rating went up three points in the second assembly tested. Both manufacturers are now selling their new higher-rated assemblies.
The difference in performance reflects the unequaled quality of design, materials and construction in Zero’s automatic door bottoms. The advanced technology common to all Zero models utilizes a concealed flat spring mechanism, which activates when the door is closed, lowering a neoprene seal insert against the floor or saddle. A protruding, hinge-side “plunger” is compressed by the frame as the door closes to activate the spring. The seal then drops in a scissors-like motion from the hinge side, adjusting to the floor from a pivoting point. This motion ensures a smooth drop without drag for a tight, secure seal against the saddle or floor. The seal retracts automatically as the door is opened.
Added features ensuring optimal seals in the High Sound models include double neoprene seals to minimize sound penetration. Zero’s unique, patented design also incorporates lock-side magnets and a steel plate, which amplify the action of the spring mechanism and ensure a controlled, uniform drop and seal. The High Sound automatic door bottom is the key component in Zero's highly regarded SOUND TRAP Door Sealing Systems, which achieve up to a 53 STC rating.
The vital importance of door bottoms in sound-rated assemblies was underscored by another door manufacturer’s account of testing several door assemblies with STC ratings ranging from the low 30s to the low 40s. Regardless of the original rating of the assembly, removal of the door bottom resulted in a rating drop to STC 20. These findings highlight the impact of any gaps in acoustical gasketing, because sound travels through even the smallest openings with very little loss.
“ZERO, no substitutes” is the sound-control standard for acoustical consultants nationwide and throughout most of the world. Zero’s SOUND TRAP systems are consultants’ gasketing of choice for optimizing high-STC applications in recording studios, performance halls and other venues requiring complete noise elimination. In the fast-growing, ever-changing acoustical market, Zero continues to supply proven solutions that satisfy the full spectrum of sound-control applications ranging from hotel entrances and communicating doors; to military installations and embassies. For schools, churches, healthcare facilities, courthouses, office buildings and other venues with growing requirements for privacy and security, Zero has tested systems to meet every need.
For more information or a copy of Zero’s catalog, contact Zero International.
