We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Galvanised steel roof curb adapter reducer 18 in curb side 21 1/2 in fan side 5 in high

Dayton

Dayton 3AZK2 Roof Curb Adapter Trap 18 in Curb Side 21 1/2 in Fan Side

SKU CH-ZNDT-G2F7K MPN 3AZK2

Reduces a 22 in fan base to fit an 18 in roof curb with galvanised steel construction

  • TypeDrain Components
  • Adapts a 22 in fan base to an 18 in roof curb
  • Galvanized steel construction resists corrosion for long outdoor service
  • Includes eight 1/4-20 Tinnerman speed nuts and bolts for secure mounting
  • 18 gauge metal thickness provides rigid structural support
  • Reducer design fits downblast, filtered supply and upblast fans

Roof Curb Adapter for Downblast Fans

This Dayton 3AZK2 adapter connects a 21 1/2 in fan base to an 18 in roof curb. It suits installers fitting downblast, filtered supply or upblast fans where the curb opening is smaller than the fan flange. The galvanised steel construction resists corrosion in outdoor mounting locations.

Reducer Limited to Specific Fan and Curb Sizes

The adapter only bridges a 22 in fan base to an 18 in curb; other combinations will not align. Its 18 ga metal thickness and fixed 5 in overall height set the structural profile, so the roof assembly must accommodate that stack height. Fastener spacing is fixed at two per side using the supplied hardware.

Verify Curb Dimensions and Fan Base Compatibility

Before ordering, confirm the existing roof curb measures 18 in square outside dimension and the fan base is 21 1/2 in wide. Check that the 2 1/2 in top flange height clears any flashing or counter-flashing already installed. Ensure the 1/4-20 bolt pattern matches the fan’s mounting holes.

Highlights

  • Adapts a 22 in fan base to an 18 in roof curb
  • Galvanized steel construction resists corrosion for long outdoor service
  • Includes eight 1/4-20 Tinnerman speed nuts and bolts for secure mounting
  • 18 gauge metal thickness provides rigid structural support
  • Reducer design fits downblast, filtered supply and upblast fans

Specifications

TypeDrain Components
BrandDayton
Model3AZK2

Questions about this item

Should I choose this adapter for an 18 in curb and 21 1/2 in fan base?

Yes, this adapter fits an 18 in curb side and a 21 1/2 in fan side, reducing a 22 in fan base to the smaller curb opening.

How does the 5 in overall height affect the installed fan assembly?

The 5 in overall height adds a short transition between curb and fan, with a 2 1/2 in top flange that bolts directly to the fan base.

What does the 18 ga galvanized steel construction mean for corrosion resistance?

The 18 ga galvanized steel provides a durable, rust-resistant barrier suited for rooftop exposure on downblast, filtered supply, and upblast fans.

Also in this aisle

People compared these

Same shelf, same checkout — eight coins and a 30-minute rate lock.