SUMMARY: A very neat way to house a submersible water pump for CPU cooling – totally secure, cheap and easy to mount inside a case.
I have had emails from some folks who think the Tupperware containers for housing a submersible pump is really cheesy. It works quite well but I have had some reservations also – not the cheesy part, but I wanted something that was more secure and easy to mount inside my case. It turns out there is an absolutely perfect container – cheap, well made, water-tight and readily available.
It is an electrical junction box that is used for underground connections (see pic below). It has no holes in it and the top comes with a rubber gasket to seal it. There are four screws in the top to secure it to the container’s body. It comes in a wide range of sizes – the one you see here is 4″x4″ and is a perfect fit for the pumps commonly used for CPU water cooling.
I found this one at Home Dept for $7.57. I bought another one at an electrical distributor that was a bit nicer for $12 (Hubbell – has nuts sunk into the container body for the bolts – the cheaper one screws directly into the plastic). I scouted around to find a method to put hose connections on it and found brass adapters that work perfectly (see pic below). You can just about do anything you want on this with the right adapters (cost less than $2 each).
I used the fittings which have a thread on it. By drilling a hole in the top slightly smaller than the diameter of the thread, you can screw the adapter into the top and it will be absolutely water tight.
I had to use a wrench to do this as you are cutting threads into the plastic and it takes some effort. I used 3/8″ x 1/4″ adapters which have a 3/8″ hose barb. The pic below shows how I mounted the pump onto the top. The thread diameter is 1/2″ and I bored a 31/64″ hole into the top.
Once you have the inlet and outlet barbs in place, you have to cut the electrical cord and drill a hole exactly the size of the cord. Thread it through the top by beveling the leading edge and pull it through. Then reconnect to the rest of the cord. This is also water tight, so you have a container which will not leak under any condition your system will encounter.
The last picture shows the pump inside the container. This is a Beckett G90AG (90 gph, lifts water 4′, about $30). This pump is larger than most so the fit is snug – smaller pumps will have lots of room. I used 3/8″ hose throughout the system to facilitate water flow. I mounted the container on a piece of foam to further isolate any noise – it’s pretty quiet and the fans mask any pump noise.