CAD Blocks, engineering letters and mechanical codes
The Recessed Dryer Vent Box a.k.a. The Dryerbox offers the architect tremendous value. It provides a UL Through Penetration Firestop System receptacle in the wall to house the dryer flex transition hose. This allows both the washer and dryer appliances to be moved back an extra 4 or more inches which in turn provides close to two extra square feet of living area and maybe solving a wall layout problem. It is simple to specify, available from more than 1,900 wholesale suppliers throughout North America and will impress your client with your conscious effort to innovate and save them money and space.
The product is commonly referred to as the Dryerbox by InOvate Technologies, Inc., under part numbers of DB-480, DB-425, DB-350, DB-4D and DB-3D. The 425 refers to the most popular model measuring 4 1/4" deep (nailing flange to rear of box). 350 is 3 1/2" deep but exhibits a "squished" or oval hole (port) to accommodate the squished 4" rigid pipe. We recommend the DB-425 for upward exhaust direction and the DB-4D for going down.
When used in conjunction with the new, more efficient Dryer-Ell, you may take full advantage of the code-allowable run length with zero fitting penalties. Specs Written by ARCAT: Master Format 95 || Master Format 04 | Specs by Zero Docs: Master Format 04
Engineering
CAD Blocks, engineering letters and mechanical codes
The Dryerbox provides some interesting advantages. Besides the many obvious benefits, the receptacle is a sensible change to the dangerous and inefficient way dryers have been exhausted for decades. The heavy molded steel construction often exceeds code requirements for air distribution components, and creates a cleaner more professional finish. Below are some letters that may be useful in permit preparation or "red-tag" challenges.
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The Dryerbox Test Report
Engineer's Letter & UL Firestop Systems Report
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Proper interpretation of the UL listing
Proper interpretation of the UL listing regarding the vent duct to be routed entirely within fire rated construction. The specific concern is Item 3 in the listing (3. Steel Vent Duct)
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Back to Back Installation for 1 Hour Walls
2006 Code Engineering specifications for installing the Dryerbox in both sides of a one hour fireresistance rated wall assembly.
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Back to Back Installation for 1 Hour Walls
2009 Code Engineering specifications for installing the Dryerbox in both sides of a one hour fireresistance rated wall assembly.
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The Technical Product Specification Sheet is providing detail information such as specific dimension, features, benefits and performance data bout the four models of The Dryerbox.
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Oval hole characteristics with model 350. Engineer's letter confirms no airflow performance impact with minor change in shape when pipe is ovalized due to restrictions caused by installing in a 2x4 wall.
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The Dryerbox is paintable. This letter by the owner clearly identifies and answers any questions relating to the paintability of the product. It also explains the lack of need to mask off the surface of The Dryerbox, saving time and expense.
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For stackable washer/dryer units or dryers mounted on pedestals, The Dryerbox can and should be installed at the proper location to allow the dryer transition flex hose to be collected and stored in The Dryerbox receptacle.
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Quickinstall guide for Stackable Washer / Dryer units for the major manufacturers.
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Sec. 504.3 of the ICC Int'l Mech Code/2009 requires a clean-out at the base of vertical risers in dryer exhaust systems. Our engineers' professional opinion is that The Dryerbox meets the requirements as a clean-out opening for the dryer exhaust system.
- 2003 IMC - International Mechanical Code (section 504)
- 2003 IRC - International Residential Code (section 1501)
- 2006 IRC - International Residential Code (section M1501)
- 2009 IRC - International Residential Code (section M1502)
- 2009 IMC - International Mechanical Code (section 504)
- 2012 IRC - International Residential Code (section M1502)
- 2012 IMC - International Mechanical Code (section 504)
- 2015 IRC - International Residential Code (section M1502)
- 2015 IMC - International Mechanical Code (section 504)
The Dryerbox carries the UL Classification mark. Click here for listing details. 
Note: The heavy 22 gauge molded steel construction exhibits similar characteristics of other sheet metal products common to the HVA/C industry and hence is generally acceptable by the governing code commissions in the mechanical code section. In some municipalities, the Dryerbox is code.
Due to the product's obvious ability to reduce the fire hazard by eliminating the potential of the flex hose from getting "kinked" or crushed, thereby improving efficiency, the Dryerbox is well-received by Building and Mechanical inspectors.