heat

38 Articles

Turn Folds Into Flowers, But Not With Origami

May 5, 2020 by 13 Comments

It is said that you’re not a sysadmin if you haven’t warmed up a sandwich on server. OK, it’s not widely said; we made it up, and only said it once, coincidentally enough after heating up a sandwich on a server. But we stand by the central thesis: never let a good source of excess thermal energy go to waste.

[Joseph Marlin] is in the same camp, but it’s not lunch that he’s warming up. Instead, he’s using the heat generated by his Folding@Home rig to sprout seeds for beautiful tropical flowers. A native of South Africa Strelitzia reginae, better known as the striking blue and orange Bird of Paradise flower, prefers a temperature of at least 80° F (27° C) for the two months its seeds take to sprout. With all the extra CPU cycles on a spare laptop churning out warm air, [Joseph] rigged an incubator of sorts from a cardboard box. A 3D-printed scoop snaps over the fan output on the laptop and funnels warm air into the grow chamber. This keeps the interior temperature about 15 degrees above ambient, which should be good enough for the seeds to sprout. He says that elaborations for future versions could include an Arduino and a servo-controlled shutter to regulate the temperature, which seems like a good idea.

The Bird of Paradise is a spectacular flower, but if growing beautiful things isn’t your style, such a rig could easily sprout tomatoes or peppers or get onions off to a good start. No matter what you grow, you’ll need to basics of spinning up a Folding@Home rig, which is something we can help with, of course.

Proprietary Fan Blows, Gets PWM Upgrade

October 26, 2019 by 13 Comments

Proprietary components are the bane of anyone who dares to try and repair their own hardware. Nonstandard sizes, lack of labeling or documentation, and unavailable spare parts are all par for the course. [Jason] was unlucky enough to have an older Dell computer with a broken, and proprietary, cooling fan on it and had to make some interesting modifications to replace it.

The original fan had three wires and was controlled thermostatically, meaning that a small thermistor would speed up the the fan as the temperature increased. Of course, the standard way of controlling CPU fans these days is with PWM, so he built a circuit which essentially converts the PWM signal from the motherboard into a phantom thermistor. It’s even more impressive that it was able to be done with little more than a MOSFET and a Zener diode.

Unfortunately, there was a catch. The circuit only works one way, meaning the fan speed doesn’t get reported to the motherboard and the operating system thinks the fan has failed. But [Jason] simply disabled the warning and washed his hands of that problem. If you don’t want to use a CPU fan at all, you can always just dunk your entire computer in mineral oil.

Super Simple Sensor Makes DSLR Camera Motion Sensitive

January 5, 2019 by 11 Comments

Do you have a need to photographically document the doings of warm-blooded animals? If so, a game camera from the nearest hunting supplier is probably your best bet. But if you don’t need the value-added features such as a weather-resistant housing that can be chained to a tree, this DIY motion trigger for a DSLR is a quick and easy build, and probably loads more fun.

The BOM on [Jeremy S Cook]’s build is extremely short – just a PIR sensor and an optoisolator, with a battery, a plug for the camera’s remote jack, and a 3D-printed bracket. The PIR sensor is housed in a shroud to limit its wide field of view; [Jeremy] added a second shroud when an even narrower field is needed. No microcontroller is needed because all it does is trigger the camera when motion is sensed, but one could be added to support more complicated use cases, like an intervalometer or constraining the motion sensing to certain times of the day. The video below shows the build and some quick tests.

Speaking of intervalometers, we’ve seen quite a few of those over the years. From the tiny to the tinier to the electromechanical, people seem to have a thing for taking snapshots at regular intervals.

Continue reading “Super Simple Sensor Makes DSLR Camera Motion Sensitive” →

Extreme Pi Overclocking With Mineral Oil

November 30, 2018 by 31 Comments

Liquid cooling is a popular way to get a bit of extra performance out of your computer. Usually this is done in desktops, where a special heat sink with copper tubing is glued to the CPU, and the copper tubes are plumbed to a radiator. If you want dive deeper into the world of liquid cooling, you can alternatively submerge your entire computer in a bath of mineral oil like [Timm] has done.

The computer in question here is a Raspberry Pi, and it’s being housed in a purpose-built laser cut acrylic case full of mineral oil. As a SoC, it’s easier to submerge the entire computer than it is to get a tiny liquid-cooled heat sink for the processor. While we’ve seen other builds like this before, [Timm] has taken a different approach to accessing the GPIO, USB, and other connectors through the oil bath. The ports are desoldered from the board and a purpose-built header is soldered on. From there, the wires can be routed out of the liquid and sealed off.

One other detail used here that  we haven’t seen in builds like this before was the practice of “rounding” the flat ribbon cable typically used for GPIO. Back in the days of IDE cables, it was common to cut the individual wires apart and re-bundle them into a cylindrical shape. Now that SATA is more popular this practice has been largely forgotten, but in this build [Timm] uses it to improve the mineral oil circulation and make the build easier to manage.

Continue reading “Extreme Pi Overclocking With Mineral Oil” →

Growing Your Own Insulation

November 21, 2018 by 45 Comments

The latest craze in revolutionary materials science is no longer some carbon nanotube, a new mysterious alloy, or biodegradeable plastic. It seems as though a lot of new developments are coming out of the biology world, specifically from mycologists who study fungi. While the jury’s still out on whether or not it’s possible to use fungi to build a decent Star Trek series, researchers have in fact been able to use certain kinds of it to build high-performing insulation.

The insulation is made of the part of the fungus called the mycelium, rather than its more familiar-looking fruiting body. The mycelium is a strand-like structure of fungus which grows through materials in order to digest them. This could be mulch, fruit, logs, straw, crude oil, or even live insects, and you might have noticed it because it’s often white and fuzzy-looking. The particular type of mycelium used here is extremely resistant to changes in temperature so is ideal for making insulation. As a bonus, it can be grown, not manufactured, and can use biological waste products as a growing medium. Further, it can grow to fit the space it’s given, and it is much less environmentally harmful than existing forms of insulation.

As far as performance is concerned, a reporter from the BBC tested it in an interesting video involving a frozen chocolate bar and a blowtorch, discovering also that the insulation is relatively flame-retardant. Besides insulation, though, there are many more atypical uses of fungi that have been discovered recently including pest control and ethanol creation. They can also be used to create self-healing concrete.

Thanks to [Michael] for the tip!

Photo of fungal mycelium: Tobi Kellner [CC BY-SA 3.0]

Gamers Rejoice: Here’s A Fix For ASUS Strix Vega 64 Thermal Issues

August 13, 2018 by 11 Comments

Every year, we demand our computers to be ever faster, capable of delivering progressively more eye-watering graphics and doing it all as reliably as ever. Unfortunately, sometimes, new designs miss the mark. [Cloakedbug] was having issues with voltage regulator temperatures on an ASUS Strix VEGA 64 — one of the latest RADEON graphics cards on the market — and decided to investigate.

Right away, issues were apparent; one of the main thermal pads was making poor contact with the FETs it was intended to carry heat for, and was poorly sized to boot. In a show of poor quality, the pad wasn’t nicely sized for the aluminium plate it was attached to, and was applied in a rather haphazard manner. Suspecting this was perhaps one of the root causes of the card running hot, the decision was made to replace the pad with something more suitable.

Specifying a thicker pad that was properly sized to the heatsink plate was the order of the day, and a couple of other smaller heatsink pads were also replaced, all with Thermal Grizzly Minus Pad 8. [Cloakedbug] reports a temperature drop of over 30 degrees C under load on the VR SOC bank, down from 115 C initially. It sounds like this will go a long way to keeping the card happy and healthy over time. Looking around the web, there’s definitely a few reports of thermal issues out there, so this could be a useful fix if you’re having trouble with the same card at home.

In the end, it’s a simple, tidy fix to an expensive piece of hardware that really should have shipped with this sorted from the factory. We’ve seen a fair few thermal fixes over the years here, like this one involving a thermal camera as a diagnosis tool.

[Thanks to Keith O for the tip!]

IoT Solar Pool Heating

July 14, 2018 by 10 Comments

A backyard swimming pool can be a great place to take a refreshing dip on a summer’s day. It can also be a place to freeze your giblets off if the sun has been hiding for even a few hours. That can make pools an iffy proposition unless they’re heated, and that starts to get really expensive in terms of upfront costs and ongoing charges for fuel or power. Unless you put the sun and the IoT to work for pool-heating needs.

Preferences vary, of course, but [Martin Harizanov] and his family clearly like their swims on the warm side. With nobody using the pool when it was below 25°C (77°F), [Martin] picked up a few bits to harness the sun to warm the water. Loops of PVC lawn irrigation tubing were tossed onto a shed roof with a favorable solar aspect and connected to the pool with a length of garden hose. The black thin-wall tubing is perfect for capturing the sun’s energy, and 200 meters of the stuff can really heat things up fast. A small pump is controlled by a microcontroller — it’s not explicitly stated but we suspect it’s a Raspberry Pi — with a pair of temperature sensors to sample the water in the pool and in the heating loop. Metrics are gathered and logged by Emoncms, an open source energy monitoring app. [Martin] says he’s harvesting about 10 kW from the sun on a good day, and that the pool water in the heating loop has gotten up to a steamy 55°C (131°F) without any other energy inputs other than the pump.

Plenty of others have made the leap to solar for pool season extension, with designs from the simple to the more complex. And if you live where the sun doesn’t shine, there’s always a compost water heater.