A Low Cost, Solar-Powered Swamp Cooler

swampCooler2014

A looming, torturous summer is preparing to bear down on many of us, making this dirt-cheap swamp cooler build an attractive hack to fend off the heat.

Though this is a pretty standard evaporative cooler, the design comes together in a tidy and transportable finished product. The base is a ~$3, 5-gallon bucket from a local hardware store with its accompanying Styrofoam liner. Three 2 1/8″ holes carved into the side of both the bucket and liner will snugly fit some inch-and-a-half PVC pipe with no need for glue.

One last cut into the lid to seat a small desk fan rounds off this build—or you can chop into the styrofoam liner’s lid if you prefer. The video demonstrates using a 15W solar panel to run the fan, and we have to admit that the cooler seems to be an excellent low-cost build. It does, however, require a frozen gallon jug inside to pump out the chilled air for around 5-6 hours per jug. Maybe one of our frugal and mathematically-inclined readers can throw out some guesstimations for the cost of stocking the bucket with a jug of frozen water a couple times a day? Video after the jump.

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Go On a Power Trip with Powerduino

powerduinoThings don’t always run the way we want them to or operate at the ideal temperature out of the box. Instead of spending extra for power controls that may or may not meet your needs, wouldn’t it make more sense to dial in the ideal level from the source? That’s what [dekuNukem] had in mind when he decided to make Powerduino, an arduino-compatible programmable power strip.

With Powerduino, [dekuNukem] can control the electrical consumption of all kinds of things without ever worrying about the irreversible deadliness of mains voltage. It actually uses a Teensy 3.1 which can be programmed with the Arduino IDE through the micro USB connector. He’s really tricked it out to the point of putting Kill A Watt meters to shame. A wi-fi module lets him control any of the outlets from anywhere, and the RTC module lets him make customized schedules for them. Powerduino has an SD card slot for logging energy consumption, and a 20 x 4 LCD screen makes it easy to directly interface with the power strip.

The Powerduino code is up on GitHub, and [dekuNukem]‘s walkthrough video is after the jump.

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Reusable Vacuum Bag Saves you Money

FTWP5L5FLROLXM5.MEDIUM

Vacuum dust bags are annoying. They’re expensive, one time use, and if you have an older vacuum cleaner, good luck finding replacements! [Karl] got fed up so he decided to make his own reusable dirt bag instead.

He’s using an old t-shirt as the new bag material but notes that you can use any other sufficiently drafty material as well — as long as it stops the dust but lets air through, you’re good! To seal the bag he’s using a piece of rubbery vinyl with a hole cut in it to seal against the intake pipe. This is sewn to the t-shirt with a piece of cardboard sandwiching the fabric. From there it’s just a matter of adding a zipper or Velcro, and you’re done!

He’s been using this filter for over a year and hasn’t had any problems with it yet — you can even wash it! While you’re at it, why not make a wet-spill attachment for your vacuum cleaner too?

 

Powering a RPi with Hydrogen

raspberryHy

Looking for a new way to power your Raspberry Pi? The raspberryHy project aims to develop a small fuel cell designed for powering the credit card sized computer. It adds a proton exchange membrane (PEM) fuel cell, a battery, and custom control electronics to the Pi.

The system takes hydrogen in from a compressed hydrogen cartridge and feeds it through a regulator. This passes the hydrogen into the PEM fuel cell at the correct pressure, and creates a potential. The control electronics boost that voltage up to the 5 V required on the Pi’s USB port. There’s also an electronically controlled purge valve which periodically exhausts the fuel cell.

There’s a few reasons you might want to run your Pi with hydrogen. Run time of the fuel cell is limited only by the amount of hydrogen you can store. In theory, you could connect a large cylinder for very long run times. Combined with a battery, this could be quite useful for running Pis in remote locations, or for long-term backup power. The raspberryHy will be presented at Hannover Fair 2014 this month.

Energy-Saving Fireplace Thermostat

[Andrian] has a boiler stove that heats water and sends it to a radiator. As the fireplace heats the water in a boiler a temperature sensor opens the a valve to send the warm water to the radiator. The radiator sends its cool water back to the boiler to be reheated. The valve is slow, so before the boiler can send all the water to the radiator, it’s getting cool water back causing the valve to close while the heat is built back up. To prevent the valve from working so hard and wasting energy, [Andrian] designed a better thermostat to control the valve operation.

The thermostat uses one LM85 temperature sensor to check the water in the boiler and another one for the ambient temperature. Once the boiler water reaches the desired temperature, the valve is opened via relay. The system waits for half an hour and then checks the boiler temperature again. The brains of this operation is an ATMega168 with a 32.768kHz crystal as the RTC. Code and PCB files are available in his repo.

We love to see these types of hacks that challenge the status quo and increase the efficiency of appliances. We applaud you, [Andrian], for turning your dissatisfaction into a positive plan of action and for sharing your experience with the rest of us!

If you want to up the eco-friendliness of heating water a bit, you could heat the water with a compost heap.

Now You’re Washing with Gas

[Michiel] likes to wash his clothes in warm water. Like a lot of machines, his draws from the cold water line and  heats it electrically. Gas is much cheaper than electricity in the Netherlands, so he wanted to be able to heat the water with gas instead. Hot-fill machines already exist, but few models are available and they’re all too expensive.  [Michiel] rolled up his sleeves and hacked his brand new washer into a hot-fill machine.

He started out thinking that he’d just connect the hot water line instead, but that proved to be too hot. He found out it needs to be about 35°C (95°F), so he decided to mix input from the hot and cold lines. Since it’s a shiny new machine, [Michiel] wanted an externally mounted system to keep from voiding  the warranty. He got two solenoid valves from the electronic bay and used a PIC16F to make them dance. He wired up a light switch on a two-panel face and used the blank plate for power and status LEDs.

[Michiel]‘s design works like a charm. The machine used to draw 2000W to heat the water, and peak usage now is as low as 200W. He noticed that the washer drew a lot of power in standby mode so he added a solid state relay and a bit more code. Now the electricity to the machine is cut after two hours and [Michiel] saves about €97 per year.

From Saw Dust to Stove Fuel

brisquit maker

[Alois Schmid] is an avid woodworker, and as such, he makes a lot of saw dust. Unfortunately, saw dust is kind of wasteful — it doesn’t burn very well unless it is compressed… so he built his own wood briquette press!

He originally looked at purchasing a machine designed for this, until he discovered they run upwards of 10,000 Euros. You could buy an amazing CNC mill for that! Needless to say, it was out of the question.

He started by purchasing a new more efficient dust extractor and an electric log splitter, and then he built an ingenious feeder system. He’s replaced the log splitter blade with a long metal dowel with a protrusion at the end (helps keeps the briquettes in one piece), which is slightly smaller than the compression tube he’s built.

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