Dryerbox RB-400
Upward Venting, Retrofit, 2x4 Wall

SKU RB-400
24 Reviews

Retro-Fit Box 400


Model 400 Retro Fit Dryerbox® - For existing construction - to be retro fit into an existing drywalled 2X4 wall. It is white powder coated and does not need to be painted. Does include a shoehorn-like tool to assist with the install. Make sure you review these instructions before purchasing as there may be obstacles and special tools needed.
  • 22 gauge aluminized steel
  • Powder coated (similar to finish on dryer appliance)
  • Top port measures 4 7/8" x 3 1/8" oval shape
  • Distance from mounting flange to rear of box is 4"
  • Overall measurements: 21" h x 11 1/2" w x 4" deep
  • Inside measures 9 1/2" wide x 18 1/4" tall
  • Two mounting 3/16" holes on bottom flange
  • Curved shoehorn-like assistance tool included

Also, be sure to check out the paintable (non powder coated) model available at select Lowe's and Menards locations.


Ratings & Reviews

24 Reviews


Happy dryer

by RB| 2/10/2023 9:17 am

Works as it should. Not an easy install, complicated by pocket door and some other obstacles, but that's why I got this in the first place. I will say that response on phone was virtually instant, cheerful and completely helpful. A pleasure doing business with this company. *I'm pretty sure it is stated somewhere on this website that an oval to round adapter is not available. It is! I just saw that exact thing on the shelf at HD. Plastic, if you trust that.


by Al| 10/16/2011 12:00:00 am

Quick install! I had to changed the diameter of my exhaust dryerflex hose (smaller diameter) to fit the hole, but other than that, it was a snap. Spray-paint the Dryerbox to red, to match the wall paint. Now it looks neat without the flex hose bundling at the back of the dryer.


by John Edward Shaulis| 4/25/2012 12:00:00 am

The space for my dryer is not deep enough for conventional connections; therefore, I was pleased to find this product available. Unfortunately, there was a pipe in the way of installation once I removed the sheet rock and I could not use it. I just left the hole in the sheetrock and connected my flex hose to it. It is not near as neat as it would have been with the Retro-Fit Box; but I was able to get the extra distance which allowed me to close the doors to my washer/dryer space.

Just what I needed

by Jdave| 3/20/2015 12:00:00 am

Great product! I have an upstairs laundry and there wasn't much room to move the washer and dryer around. It was difficult to match the dryer vent up to my dryer exhaust since the vent came from the basement up and through the wall horizontally. I installed the DryerBox upside down since my vents came up from the basement, then used aluminum flex pipe to make a vertical loop up and then down to the dryer with a 90 degree elbow on the dryer exhaust. My only issue was I wished I had gotten the 2x6 box since there was a 2x6 framed utility wall behind the laundry room. Fussing with that oval hole was a bit of a pain. Now I no longer have dust and lint escaping into my home. I also replaced the 10 feet of vinyl hose in the basement to the exterior with solid 4" galvanized duct pipe while I was at it.


by Fran Doak| 7/14/2012 12:00:00 am

A carpenter friend installed our DryerBox and was very impressed with it. We love it and now our dryer sits right up against the wall and we don't have the worry of built up lint! Thank you! Thank you!

retro dryer box

by chuck| 4/29/2014 12:00:00 am

dryer box very easy to install along with dryer wall vent would highly recommend both proudcts very satisfied


by Bgmc| 9/7/2020 12:00:00 am

Had this installed by a handyman as the set up I had left very little room for attaching the vent and even less room for the hose. He said install went smoothly and he very much liked the product. In addition, I'd called in with questions prior to ordering and customer service was incredibly helpful! (Good thing I called as I was on the verge of ordering the wrong product!) 5 stars!

Model 400 Retro-fit 2x4 dryer box

by Dax| 9/21/2014 12:00:00 am

Fits cleanly between the 2x4 studs. Allows vent hose to sit between walls and also allows dryer to now fit cleanly up against the wall. We love it made the laundry room redo quick, safe, and easy.

Great Product

by HKS| 10/7/2011 12:00:00 am

While moving the old dryer, I discovered that the dryer exhaust pipe was force fully squeezed by the builder within the 4 in dry wall causing the lint to fill the dry wall cavity. I knew this was a fire hazard, so I needed a better solution and after searching the web I found this Drybox, Its real easy to install with instruction on the back of the product and a video online, has a nice white enamel look and helped me gain extra room to move around the tight laundry room.

Dryer Box for wall

by Jennifer Davis| 2/12/2014 12:00:00 am

product is what I ordered and was easy to install. i also received the item in a timely manner.


by Judson| 5/4/2011 12:00:00 am

Wonderful - fairly EZ install - would be nice to have a support of some sort on the top -


by Manuel Pozo| 5/1/2011 12:00:00 am

Just what I needed. I found your product by accident. I was looking at a video on how too install a drain for a washer

In wall Dryer Retro-Fit Box

by Mid Carolina Chimney Service| 4/30/2015 12:00:00 am

As a contractor we often find homes with new dryers that are larger then the space the laundry room was originally built for. This product allows the home owner the few extra inches needed to have the appropriate fit and not crush the vent connector. Great product for that professional installation.

Model 400 Retro-Fit Box

by Paul Shireman| 6/22/2011 12:00:00 am

Easy install. Makes a neat looking installation

Excellent Product

by Rob| 5/2/2013 12:00:00 am

I own my own appliance service company for 25 years and have seen the problem of crimped and mashed vent many times. I bought this for my own dryer installation. After installing the dryer box and reinstalling the dryer I gained about 3 inches in usable space in front of the dryer. Not that difficult to install, would like to see pre-drilled holes at the top corners. Otherwise great product and have already recommended to several of my customers.


by Mark| 9/3/2014 12:00:00 am

This product is just what I needed. My house is new. Seems most builders use this product in my market area except my builder. Since the run from wall to roof vent was 30' I needed this product to be safe from heating element burnout. Whirlpool says each time you have a 90 degree vent angle you lose 9' in recommended max vent distance. I hired my heat/air guy to install @ $150..well worth it.

The dryer box rocks!!!

by Lori| 5/30/2013 12:00:00 am

I have a small laundry room like everyone else in Florida. It is essentially the access hallway to the garage. I had a Duet washer dryer pair on pedestals since 2000 and it was time to upgrade. Problem is all the front loading pairs are larger now than they were then. I found a great LG set that fit the space however the dryer has a vent sensor and no matter how I tried I couldn't keep the hose from kinking. I tried an expensive venting system that was supposed to rotate as you pushed the dryer back but after a day of frustration trying to get the dryer situated I finally gave up and started looking online and found this little wonder. I called my handyman because I knew it was more of a job than I could handle alone. I measured the wall and knew it was only 4" deep so I ordered the correct box. We ran into two issues. First the vent was strapped to the stud to its right and this box is made for a stud attached on the left. The second issue was more of our mistake. Instead of putting the box to the floor through the baseboard we decided to raise it up because the dryer is on a pedestal which raises the height of the vent on the dryer. The left access was resolved by cutting a much larger hole in the drywall and adding a couple of aluminum elbows to have the vent enter the top left of the dryer box so we have a little extra sheet rock work and painting to do. By raising up the box we thought it would allow more room for the hose to assume its upward position but it tended to drop below the dryer box when we pushed the dryer into place so it took several attempts to get it in correctly but once we did it was perfect!!! I think I finally have good dryer venting that I have never had before in this house. I have tested the vent sensor several times now since installation a month ago and it always indicates that the vent is wide open. My only suggestion is to make a longer model dryer box for pedestal mounted dryers. This is a great invention. My electric bill already dropped more than $50 and I'm convinced it was because the dryer only runs half as long now. THANK YOU!

Very Functional Item And Makes Neat Appearance

by Mike| 8/16/2011 12:00:00 am

Very well made. And an easy install. My sisters dryer is in a narrow hallway and getting the dryer closer to the wall by 5 inches has made a big difference in walkway. Looks good too. Clean and neat. Would buy again if needed.

My secret weapon

by Richard| 3/5/2015 12:00:00 am

This product allowed me to get a job in which the designer had forgotten to put the 3 dryer vents into the job when it was being constructed. The other contractors I was bidding against all said it will have to come through the drop ceiling and the 4’’ pipe will have to be exposed. We were contacted to see if we could find a way to retrofit the 3 – 4’’ pipes into the wall space so that it wouldn't be seen. The other obstacle we were up against was that the city required that all 3 dryers had a cleanout which really complicated the entire project. After doing some research on the internet I came across this product and they provided me with a letter that I presented to the city as being a legal devise that met the strict requirements of the clean out box. The city approved the idea based on the letter that was provided to me so I submitted my bid. Even though my quote was much higher this secret weapon allowed us to get the project and we won the bid. This product allowed us to complete a job that years ago would have been impossible. Thanks In-O-Vate Technologies for allowing me to add another product to my list of things we can now do. In the end the people this job was for were blown away when they saw the finished product and the city passed it with flying colors.


by Rob Ream| 7/19/2012 12:00:00 am

After seeing many add's in trade magazines, I had a situation where I could put one to use and it worked perfectly. It cured the problem of the dryer duct getting kinked or disconnected. I will definitly use this product again. Thanks, Rob.


by Ron Slota| 4/2/2012 12:00:00 am

Incorrectly ordered Model 400RB based on product description-really needed and installed model 3D. website confusing unless you happen upon dryerbox selector page. Product excellent! What a wonderful idea- Our previous owners had a stud bay filled w/ lint-shocking to discover, glad it's corrected. Thanks In-O-Vate.


by Ryan| 3/20/2015 12:00:00 am

Really happy with my order.. keeps a nice clean look and worked well as a retrofit solution. I think this is the best thing I've seen for cleaning up a typically messy area with the vent getting smashed to the wall, etc..

Review of Model 400 Retro-Fit Box 2x4

by Walt| 12/29/2011 12:00:00 am

It seems I always run into problems when everyone else has an easy install.Yes,there should be some way to support the top. I had to build an extra partial stud on one side. The 8 inch hole to see inside the wall turned out to be 4 foot high by 16 inch. The pipe in the wall was solid, on the wrong side, and strapped to the stud on the right. Needed a section of flexible aluminum pipe to cross over to the other side of the unit. Lots of other things but limited space.

Construction supervisor

by Thomas Schuyler| 4/4/2012 12:00:00 am

I purchased my first dryer box and installed it on an interior wall for a fire/remodel. I am really pleased with the quality of the unit and the satisfaction of the homeowner. In a small home like this it gives the homeowner the extra few inches that really make a difference. I will use this again on my next project.