Zero International 320AA 36" S...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$132.00
$65.16
Zero 320 Regular Duty Automatic Door Bottom Clear Anodized Aluminum Finish

Zero International 320AA 36" Sill Protection Automatic Door Bottom with Neoprene Insert - Mortised, Fire Rated

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Model: 320AA36

In Stock (leaves warehouse same day if ordered before 3pm ET)

$132.00
$65.16
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Zero International 320AA 36" Sill Protection Automatic Door Bottom with Neoprene Insert - Mortised, Fire Rated

The Zero International 320AA is a 36" sill protection automatic door bottom engineered for mortised installation on commercial doors requiring a durable, self-activating seal. Featuring a neoprene insert and a maximum effective drop of 1", this regular-duty unit is fire rated and rated for 5 million cycles, making it suitable for high-traffic commercial applications. Finished in Clear Anodized Aluminum and supplied with #320 end caps, the 320AA delivers dependable sealing performance against the floor or saddle throughout its extended service life.

Key Features

  • Door Width: Designed for 36" doors for accurate fit and seal coverage.
  • Maximum Effective Drop: 1" drop provides a tight seal against the floor or saddle even on uneven surfaces.
  • Heavy-Duty Durability: Rated for 5 million cycles for long-term reliability in commercial door applications.
  • Fire Rated Construction: Fire rated design supports use in applications requiring code-compliant door hardware.
  • Neoprene Insert: Neoprene seal compresses tightly against the floor or threshold for effective sill protection.
  • Mortised Mount: Regular duty mortised installation integrates cleanly into the door bottom for a low-profile finish.
  • Patented Automatic Activation: ZERO's patented automatic door bottom technology uses an adjustable plunger that compresses against the door frame as the door closes, activating a concealed flat spring mechanism that drops the seal smoothly from the housing in a scissor-like motion and retracts automatically when the door is opened.
  • Hinge-Side Activation Sequence: The concealed spring mechanism activates the insert seal on the hinge side first, preventing the seal from dragging along the floor or threshold and avoiding door hang-up or closing delay.
  • Included Hardware: Supplied with #320 end caps for a complete, finished installation.

Certifications & Compliance

  • Fire Rated
  • Rated for 5 million cycles

Technical Specifications

  • Commercial/Residential: Commercial
  • Product Group: Door Trim and Accessories
  • Product Subgroup: Door Bottom Sweeps and Door Shoes
  • Department: Door Hardware

Typical Applications

  • Commercial Office Buildings
  • Educational Facilities
  • Healthcare Institutions
  • Retail Establishments
  • Industrial and Warehouse Facilities
  • Multi-Tenant Residential Properties
  • Government and Municipal Buildings

Why Zero International 320AA?

Zero International automatic door bottoms deliver professional-grade reliability with a fire rated, neoprene-sealed design rated for 5 million cycles of dependable operation. The patented scissor-motion activation mechanism ensures consistent sealing performance and smooth door operation, making the 320AA a dependable choice for demanding commercial applications where sill protection and code compliance are essential.

Manufacturer Resources

Zero Full Line Catalog

Product Specs

Commercial/Residential:
Commercial
Product Group:
Door Trim and Accessories
Product Subgroup:
Door Bottom Sweeps and Door Shoes
Product Type:
Door Bottom
Department:
Door Hardware

Zero International 320AA36 – Frequently Asked Questions

1) Will the Zero 320AA automatic door bottom seal a floor that isn't level?
The 320AA has a maximum effective drop of 1 inch, so the neoprene insert can travel down that far to meet an uneven floor or a saddle. That drop is what buys you tolerance on a worn slab or a threshold that sits proud. Measure the worst gap between the door bottom and the finish floor along the full 36 inch width; anything inside 1 inch is within range, anything beyond it is not going to seal and you want a different bottom treatment.
2) Is the Zero 320AA mortised into the door or does it surface mount?
Mortised. The 320AA housing sets into a routed pocket in the bottom edge of the door, which is why it finishes flush and low profile rather than hanging below the door face. That means door prep is part of the job: you need to be able to rout the bottom rail for the full 36 inch length. If the door can't be taken down or the bottom rail won't take a mortise, a surface applied door bottom is the option instead, not this one.
3) Can I use an automatic door bottom on a fire rated door assembly?
The 320AA is a fire rated automatic door bottom, so it's built for openings where the door assembly has to hold a rating. That matters on stair doors, corridor doors and cross-corridor smoke separations in healthcare and education work, where a plain brush sweep often isn't acceptable. Confirm the rating requirement on the opening against the door manufacturer's listing for the assembly you're working on.
4) How does an automatic door bottom actually drop, and will it drag on my floor?
An adjustable plunger at the hinge end of the 320AA compresses against the frame as the door closes, releasing a concealed flat spring that lowers the neoprene insert out of the housing in a scissor motion, then pulls it back up when the door opens. The seal drops on the hinge side first, so it doesn't skate along the floor or the threshold as the door swings shut. That sequence is why it doesn't hang up the door or slow the closer down, which is the usual complaint with a fixed sweep on a tight floor.
5) Will an automatic door bottom hold up on a high traffic commercial door?
Rated to 5 million cycles. On a corridor or lobby door taking heavy daily use, that's the number that matters more than the seal material, because the failure mode on these is the spring mechanism giving up, not the neoprene wearing out. The 320AA is a commercial unit, sized for office buildings, schools, healthcare, retail, warehouses and multi-tenant residential.
6) What comes with the Zero 320AA, and what else do I need to order to finish the install?
The 320AA ships with #320 end caps and the neoprene insert already in the housing, in a clear anodized aluminum finish. What is not in the box is the door prep: you supply the routing and the fasteners appropriate to the door construction. If you're sealing the whole opening rather than just the sill, the head and jamb seals are separate items.
7) Is neoprene the right seal material for a door bottom, or should I be looking at a brush sweep?
Neoprene compresses against the floor or threshold to close the gap, so it seals against air, smoke and light far better than a brush, which lets air through by design. The tradeoff is that a compression seal only works if it's off the floor when the door is moving, which is exactly what the automatic drop on the 320AA does. Brush sweeps are for keeping debris out on a door where nothing needs to be sealed; a neoprene automatic bottom is for a door where the gap has to close.
8) What finish is the Zero 320AA and will it show once the door is hung?
Clear anodized aluminum, which is the standard mill look and reads neutral against most aluminum and hollow metal doors. Because the 320AA mortises into the bottom edge, the only part visible in service is the thin housing edge and the #320 end caps, so the finish match matters much less here than it would on a surface applied sweep.
9) Can I standardize the same automatic door bottom across a building with different door types?
The 320AA works wherever the door bottom rail can be mortised and the floor gap stays inside the 1 inch drop, which covers most commercial office, school, healthcare, retail, industrial, multi-tenant residential and municipal openings. Where it breaks down across a fleet is door width, since length is fixed at 36 inches per unit and is cut down rather than extended, and doors you cannot rout. Take a width and a floor gap on every opening before you settle on one part number for the whole building.
How fast can I get the Zero International 320AA36 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Zero International 320AA36 come with a warranty?
Absolutely. The Zero International 320AA36 is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Zero International 320AA36?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
Why buy the Zero International 320AA36 from ZenSupply?
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