heating

22 Articles

Internal Heating Element Makes These PCBs Self-Soldering

January 18, 2023 by 53 Comments

Surface mount components have been a game changer for the electronics hobbyist, but doing reflow soldering right requires some way to evenly heat the board. You might need to buy a commercial reflow oven — you can cobble one together from an old toaster oven, after all — but you still need something, because it’s not like a PCB is going to solder itself. Right?

Wrong. At least if you’re [Carl Bugeja], who came up with a clever way to make his PCBs self-soldering. The idea is to use one of the internal layers on a four-layer PCB, which would normally be devoted to a ground plane, as a built-in heating element. Rather than a broad, continuous layer of copper, [Carl] made a long, twisting trace covering the entire area of the PCB. Routing the trace around vias was a bit tricky, but in the end he managed a single trace with a resistance of about 3 ohms.

When connected to a bench power supply, the PCB actually heats up quickly and pretty evenly judging by the IR camera. The quality of the soldering seems very similar to what you’d see from a reflow oven. After soldering, the now-useless heating element is converted into a ground plane for the circuit by breaking off the terminals and soldering on a couple of zero ohm resistors to short the coil to ground.

The whole thing is pretty clever, but there’s more to the story. The circuit [Carl] chose for his first self-soldering board is actually a reflow controller. So once the first board was manually reflowed with a bench supply, it was used to control the reflow process for the rest of the boards in the batch, or any board with a built-in heating element. We expect there will be some limitations on the size of the self-soldering board, though.

We really like this idea, and we’re looking forward to seeing more from [Carl] on this.

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Keeping An Eye On Heating Oil

November 2, 2022 by 70 Comments

Energy costs around the world are going up, whether it’s electricity, natural gas, or gasoline. This is leading to a lot of people looking for ways to decrease their energy use, especially heading into winter in the Northern Hemisphere. As the saying goes, you can’t manage what you can’t measure, so [Steve] has built this system around monitoring the fuel oil level for his home’s furnace.

Fuel oil is an antiquated way of heating, but it’s fairly common in certain parts of the world and involves a large storage tank typically in a home’s basement. Since the technology is so dated, it’s not straightforward to interact with these systems using anything modern. This fuel tank has a level gauge showing its current percentage full. A Raspberry Pi is set up nearby with a small camera module which monitors the gauge, and it runs OpenCV to determine the current fuel level and report its findings.

Since most fuel tanks are hidden in inconvenient locations, it makes checking in on the fuel level a breeze and helps avoid running out of fuel during cold snaps. [Steve] designed this project to be reproducible even if your fuel tank is different than his. You have other options beyond OpenCV as well; this fuel tank uses ultrasonic sensors to measure the fuel depth directly.

Is This The Oldest Open Source HVAC Project In Existence?

August 22, 2022 by 19 Comments

Homebrew HVAC systems are one of those projects that take such a big investment of time, effort and money that you’ve got to be a really dedicated (ideally home-owning) hacker with a wide variety of multidisciplinary skills to pull off an implementation that can work in reality. One such HVAC hacker is [Vadim Tkachenko] with his multi-zone Home Climate Control (HCC) project that we covered first back in 2007. We now have rare opportunity to look at the improvements fifteen years of part-time development can produce, when a project is used all day, all year round in their own home. At the start, things were simple, just opening and closing ventilators with none of those modern MQTT-driven cloud computing stuff. Continue reading “Is This The Oldest Open Source HVAC Project In Existence?” →

The Benefits Of Displacement Ventilation

July 7, 2022 by 27 Comments

The world has been shaken to its core by a respiratory virus pandemic. Humanity has been raiding the toolbox for every possible weapon in the fight, whether that be masks, vaccinations, or advanced antiviral treatments.

As far as medicine has come in tackling COVID-19 in the past two years, the ultimate solution would be to cut the number of people exposed to the pathogen in the first place. Improving our ventilation methods may just be a great way to cut down on the spread. After all, it’s what they did in the wake of the Spanish Flu.

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Custom Controller Ups Heat Pump Efficiency

March 25, 2022 by 59 Comments

Heat Pumps are an extremely efficient way to maintain climate control in a building. Unlike traditional air conditioners, heat pumps can also effectively work in reverse to warm a home in winter as well as cool it in summer; with up to five times the efficiency of energy use as a traditional electric heater. Even with those tremendous gains in performance, there are still some ways to improve on them as [Martin] shows us with some modifications he made to his heat pump system.

This specific heat pump is being employed not for climate control but for water heating, which sees similar improvements in efficiency over a standard water heater. The problem with [Martin]’s was that even then it was simply running much too often. After sleuthing the energy losses and trying a number of things including a one-way valve on the heating water plumbing to prevent siphoning, he eventually found that the heat pump was ramping up to maximum temperature once per day even if the water tank was already hot. By building a custom master controller for the heat pump which includes some timing relays, the heat pump only runs up to its maximum temperature once per week.

While there are some concerns with Legionnaire’s bacteria if the system is not maintained properly, this modification still meets all of Australia’s stringent building code requirements. His build is more of an investigative journey into a more complex piece of machinery, and his efforts net him a max energy usage of around 1 kWh per day which is 50% more efficient than it was when it was first installed. If you’re looking to investigate more into heat pumps, take a look at this DIY Arduino-controlled mini heat pump.

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Lowering The Electricity Bill By Mining Cryptocurrency

March 1, 2021 by 119 Comments

Wherever you are in the world, the chances are that a large portion of your utility bill is for heating. This was certainly the case for [Christian Haschek], who realized he can use a cryptocurrency mining rig to offset some of his heating costs.

[Christian]’s central ventilation and water heating is handled by a heat pump, which uses a lot of electricity, especially in the Austrian winter. When it draws in cool air, it first needs to heat it to the thermostat temperature before venting it to the house. Cryptocurrency mining rigs are also heavy electricity users, but they also produce a lot of heat, which can be used to preheat the air going to the heat pump. [Christian] had four older AMD R9 390 GPUs (equivalent to the Nvidia GeForce GTX 970) lying around, so he mounted them in a server case and piped the heat pump’s air intake through the case.

At the time he did the tests, earnings from mining were enough to cover half of his heating bill, even after paying for the mining rig’s electricity. That is not taking into account the electricity savings from the preheated air. He only shows the results of one evening, where it dropped his electricity usage from around 500Wh to below 250Wh. We would like to see the long-term results, and it would be an interesting challenge to build a model to calculate the true costs or savings, taking into account all the factors. For instance, it could be possible to save costs even if the mining rig itself is running at a slight loss.

Of course, this is not a new idea. A quick internet search yields several similar projects and even some commercial crypto mining space heaters. We do like the fact that [Christian] reused some hardware he already had and integrated it into his central heating rather than using it as a mobile unit.

When [Christian] isn’t building crypto heaters, he can be found flooding phishing scams with fake data, or tracking down corporate spies.

A Heat Reclaimer For Your Woodstove; The One Thing It’s Not Is Cool

January 30, 2021 by 27 Comments

It’s the middle of winter for those of us who live in the Northern Hemisphere, which naturally turns minds towards heating, or sometimes the lack of it. It’s particularly difficult for those who rely on a wood stove to escape the feeling that perhaps most of that hard-won heat may be whistling up the chimney rather than keeping them warm. It’s a problem [Lou] has addressed with his DIY chimney heat reclaimer.

As can be seen from the video below the break, his stove appears to be in a workshop, and has a long single-wall metal stove pipe. Over the outside of this he’s placed a pair of T pieces joined by a longer length of pipe all of a larger bore, and a mains-powered fan forces air through this air jacket. The result is a continuous flow of hot air that he claims delivers a 45% heat reclamation. We’re curious though whether the reduction in flue temperature might cause extra tar condensation and thus the build-up of flammable material further up the chimney. The stove itself is a double barrel affair with access for smoking, and the video describing it is worth a look in itself.

Whatever the stove, be sure to ensure a constant supply of fuel!

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