When my orange Home Depot bucket DIY swamp cooler started running, the stream of cool air blasting on my face was a very refreshing change from the oppressive heat of this southern California summer. However, this crude home-built unit does have some room for improvement, and I brought it into a local maker meet to seek ideas. Here it is at the meet sitting next to its inspiration, an earlier unit built out of a TrueValue white bucket.

First problem: the cooling pad imparts a scent on the air stream. It’s not a bad smell – I describe it as bales of hay – but it gets pretty strong as the cooler runs. There’s a chance this will fade with use, but right now it definitely gets strong enough to be a turnoff. Especially when I am smelling it all the time.

Not helping with the above problem: water cycling through the unit sometimes drips out of holes. On solid surfaces, this collects as a puddle and has to be wiped up. But on carpeted surfaces if unchecked this water will soak into the carpet and underlying padding, making the room smell like bales of hay even in the absence of the cooler.

Also not helping: when transporting the cooler (like, say, to the maker meet) water may slosh out of the side. If this water soaks into the car’s upholstery, the car will start to smell like hay, too.

An idea to address dripping is to put a fine mesh between the bucket and the pad, such as the one installed on the white unit. This reduces but does not completely eliminate the water issue. A second potential line of defense is to build some sort of small catch gutter around bucket perimeter to catch and drain water back into the bucket. A small catch rim would be enough to handle small drips.

Lastly, the rate of evaporation isn’t high enough to require a constantly running pump. For better energy efficiency, the pump only needs to run intermittently, but that requires smarts and control equipment absent from this bargain-basement build.

This was an instructive (and cheap) first attempt at a home-built swamp cooler. There may be an improved iteration in the future, but for now it works well enough.

And once again, I’m reminded that summers in southern California can get really, really hot. Sitting in the heat trying to comprehend details of ROS gets very tiresome very quickly. Normal house fans can’t cut it anymore. Air conditioning is an obvious solution, but it racks up my electric bill. But in the relatively dry climate of California, there is another option: the evaporative cooler (“swamp cooler”).

I could buy one, but a local maker tried the DIY option and that looked like it might be interesting. The key find enabling such an experiment is a cooler pad designed for the purpose and available for just $5.

My first attempt was to put that pad inside an old 10-gallon pail already in the house and just collecting dust. Unfortunately, the plastic for the pail proved too brittle to withstand drilling. Whether it is from old age or if the compound is fundamentally brittle I can’t tell, and the actual reason doesn’t matter anyway.

Plan B: Use a cheap Home Depot 5-gallon bucket. Using rulers to measure out spacing, ventilation holes were drilled in the bucket. It was tedious but surprisingly took less time than I had feared.

Once holes were drilled, the pad was placed inside the bucket along with some water. A cheap pump designed for decorative water fountains were placed inside along with some hoses to circulate water, keeping the cooling pad damp.

For air circulation: I first tried to adapt my house fan but it proved too unwieldy. Moving on to plan B, I used a computer cooling fan salvaged from a dead ATX power supply. It bolted directly to the bucket lid and, with aid of a simple 3D-printed adapter to a flexible dryer duct, its output air can be directed to where it does the most good. Here’s my cooler, next to its inspiration.

The output air stream feels a lot cooler than ambient air, so the project is an overall success. But there is room for improvement…