Ventilated Cat Litter Box




Anyone who lives with an indoor cat knows how bad it can be when the cat uses its litter box. A cat box is unsightly to see, and worse to smell.

Step 1: Using Dead Space in Wall

My first step in addressing the problem was to put the cat box out of sight in a dead space under our stairs. I cut out the drywall between studs and made a plywood box to fit behind the space (16h 14w 23d inside dims). I wanted the cat to be willing to go in and have room to turn around etc. so the whole affair is a bit larger than a standard cat box.

I made a waterproof litter-box out of 1/8" plexiglass to fit in the box, be fairly high to contain a lot of litter, but not so high the cat would be discouraged from using it (8h 13 1/2w 20d). I trimmed the room side of the drywall cut-out with oak and it looked pretty good. But it was always obvious when the cat had made serious use of the box - it stunk.

Step 2: The Ventilator

The next step was to build a powered ventilator so a fan would suck air out of the box and away from the room when needed. I got some drainage tubing with the idea the fan should be placed away from the box so as to not scare the cat. I bought a 12 volt muffin fan at the electronics store. This one came with LEDs that came on when the fan was powered and I ended up using them. I got a cheap security light controller - the kind that senses motion (based on infrared heat sensing actually) and a plug adaptor that would screw into the light socket.

I cut a big hole toward the back of the box top, stapled on some wire mesh, and attached the tube with duct tape. I disassembled the motion sensor from the light sockets and mounted the sensor inside the box, wires led upward and out of the box. I made a tiny hole in the oak trim for one of the LEDs. 120v power comes from a plug in the basement, and 12 volt power comes from a power converter (wall bug) plugged into the light socket. When motion is detected, the light socket is powered, the converter makes 12 volts, the LEDs come on (one I can see in the basement and one within the oak trim), and best of all, the fan comes on. I've set the security light adjustment to medium sensitivity and maximum duration (12 minutes). 12 minutes really isn't enough to kill the stink but it sure helps.

Step 3: Simplify

Every time I would walk by the cat box I'd still notice the stink. 12 minutes of vent time just wasn't cutting it. So I bypassed the ever-so-clever motion detector and now the vent runs 24x7. I checked and it draws 3 watts. Well worth it because there is no stink at all in the room.



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    8 Discussions


    4 years ago

    Let me start by saying I think you did a fantastic job of it. Very nicely done.

    Having said that, and not intending to bust your balloon, let me tell you about a trick I learned from a cat breeder we bought a pure blood Burmese from.

    The breeder used nothing but wood pellets for litter. The kind used in pellet stoves. These pellets are made of sawdust mixed with guar gum and compressed into the pellet shapes. Guar gum holds them together and it also reacts with cat urine and completely neutralizes any odor. You can buy these pellets commercially under the name Pine Fresh but it's kinda pricey. Regular, non-food grade pellets are much cheaper.

    I do recommend buying the special litter box sold by Pine Fresh, though. You can Google it. It's actually 2 nesting plastic boxes and the inner box has a mesh bottom that allows the sawdust to fall through into the bottom box. Once the cat urine and guar gum have done their thing, the pellet breaks up into just sawdust. Emptying the litter box is very simple - just shake it until the sawdust has fallen through. This shaking will bring any solids to the surface for easy scooping and disposal.

    My wife and I have used this method for some years, now, and I defy you or anyone detecting any odor in our home from the presence of a cat living there. We love it and recommend it highly.

    Hope this helps....

    3 replies

    Reply 1 year ago

    I agree I LOVE wood pellets, buying a pallet at a time at Menards you can also get a discount in addition to sale prices 3.99 to 4.99 per forty pound bags.


    Reply 3 years ago

    Well Gol durn. I've got to try that! I've already got a bag of pellets for my woodgas lawn tractor. One of our cats will poop on the floor if the box is not to her liking.


    Reply 4 years ago on Introduction

    I like this idea, and even tried it for a while. But we had a cat who absolutely refused to use the box with the pellets in it so we had to go back to the old way. Unfortunately that cat has passed now so I may revisit the idea. It was very convenient, and even if we decided it was time for a total box change, the pellets were extremely cheap compared to litter. A huge bag (like bag of mulch size) was only $4.


    4 years ago

    We have a box with a door and a carbon filter. When the cat does his "serious" business, you know it! From two rooms away. We can't vent to the outside, but might consider a fan over the top through a box containing stick ups.


    4 years ago on Introduction

    Now that is a solution born out of desperation.

    Sometimes I have to wonder what in the world have they been eating???

    I notice what appears to be a cat door in your main picture. Some would ask why doesn't the cat just go outside? But more than likely the cat comes inside, uses the box and then goes back out. They have to keep us trained ya know.

    2 replies

    Reply 4 years ago on Introduction

    I wonder what happened to the reply I thought I did this AM?? Anyhow, the cat door was for cats now long gone and is decommissioned. It leads to the garage.


    Reply 4 years ago on Introduction

    That cat door doesn't go outside. It goes to a closed room under the stairs where I assume the cat box used to be.....