This fog chiller is a great combination of size and function, but is still cheap and easy to build. It will definitely add some add some spookiness to your halloween graveyard. I have constructed other fog chillers, including the bigger trash can models, but this one performs the best.
The purpose of a fog chiller is to drop the fog temperature as much as possible so the fog "sinks" to the ground, being heavier than the ambient air. Straight out of the fog machine, fog is hot and will rise quickly. In the end, fog cooler performance comes down to cooling surface area. The problem I've had with big trashcan units, is that the fog is piped in relative comfort, through a coiled tube that is surrounded by ice. This results in less heat transfer, as the fog cruises through the tube unimpeded and is only somewhat cooled by the tubing wall.
With this design, the fog directly filters through a bed of individual ice cubes, which results in a much higher heat transfer. Look at it this way, if you have a glass of hot water, it will chill much faster if you drop a handful of ice directly into the glass, rather than surrounding the glass with a handful of ice.
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Step 1: Materials and Tools
- 2" PVC pipe
- 2"-to-4" PVS adapter. I use this to catch the output from the fog machine
- 2" pvc elbow
- 3/4" PVC pipe or wooden dowel or miscelenious pieces of wood to support mesh
- mesh plaster lath or other stiff wire screen. HD has rolls of lath for a couple bucks and I found this to be the cheapest option.
- optional duct tape or stick-on foam tape to seal cooler lid
- 2 1/4" hole saw
- hacksaw to cut PVC pipe
- glue gun
- wire snips to cut mes
Step 2: Build It!
1. Drill two holes in the cooler with the 2 1/4" hole saw. You can see the location for the holes from the pictures. The hole in the side of the cooler is the input for the hot fog.
2. Insert the PVC pipe. If the fit is tight, you are good. If not, you can seal with some silicone.
3. On the input side, use the 90 degree elbow and run the PVC up towards the top of the cooler.
4. Cut the mesh to size for a tight fit in the cooler. You'll need to cut a hole for the input pipe
5. Hot glue pieces of PVC to the bottom of the cooler. This will support the mesh a few inches above the cooler floor, which will support in turn the weight of the ice.
6. If you want you can add some foam insulation tape around the lid of your cooler to get a better seal. My cooler was cheap and does not have a great factory seal. Duct tape will also work.
7. I use the 4"-to-2" adapter on the input pipe to catch the fog from the fog machine. This leaves a bit of an air gap which is OK and actually desirable.
8. Add ice to the cooler and enjoy that sweet, low hanging cemetery fog. My cooler takes roughly two 20 pound bags of ice. You may want to route the fog through some additional piping to slow it down, as a lower velocity will also help it to hang low. Some people even use a simple trash bag taped to one end, with a slit at the other end for the fog to exit.