heating

25 Articles

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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Simple Induction Heater Helps With Homebrew Shrink-Fitting

October 26, 2020 by 14 Comments

Machinists have a lot of neat shop tricks, but one especially interesting one is shrink-fitting tools. Shrink-fitting achieves an interference fit between tool and holder by creating a temperature difference between the two before assembly. Once everything returns to temperature, the two parts may as well be welded together.

The easiest way to shrink-fit machine tooling is with induction heating, and commercial rigs exist for doing the job. But [Roetz 4.0] decided to build his own shrink-fitting heater, and the results are pretty impressive. The induction heater itself is very simple — a 48 volt, 20 amp power supply, an off-the-shelf zero-voltage switching (ZVS) driver, and a heavy copper coil. When the coil is powered up, any metal within is quickly and evenly heated by virtue of the strong magnetic flux in the coil.

To use the shrinker, [Roetz 4.0] starts with a scrupulously clean tool holder, bored slightly undersized for the desired tool. Inside the coil, the steel tool holder quickly heats to a lovely deep brown color, meaning it has gotten up to the requisite 250-300°C. The tool is quickly dropped into the now-expanded bore, which quickly shrinks back around it. The advantage of this method over a collet or a chuck is clear in the video below: practically zero runout, and the tool is easily released after another run through the heater.

You say you’ve got no need for shrink-fitting tools? How about stuck bolts? Induction heaters work great there too.

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Arduino Reduces Heating Costs

June 16, 2020 by 29 Comments

While almost everyone has a heater of some sort in their home, it’s fairly unlikely that the heat provided by a central heating system such as a furnace is distributed in an efficient way. There’s little reason to heat bedrooms during the day, or a kitchen during the night, but heating systems tend to heat whole living space regardless of the time of day or the amount of use. You can solve this problem, like most problems, with an Arduino.

[Karl]’s build uses a series of radiator valves to control when each room gets heat from a boiler. The valves, with a temperature monitor at each valve, are tied into a central Arduino Mega using alarm wiring. By knowing the time of day and the desired temperature in each room, the Arduino can control when heat is applied to each room and when it is shut off, presumably making the entire system much more efficient. It also has control over the circulating pump and some of the other boiler equipment.

Presumably this type of system could be adapted to a system which uses a furnace and an air handler as well, although it is not quite as straightforward to close vents off using a central unit like this as it is to work with a boiler like [Karl] has. With careful design, though, it could be done. Besides replacing thermostats, we can’t say we’ve ever seen this done before.

Thanks to [SMS] for the tip!

An Efficient Homemade Wood Furnace

November 30, 2019 by 17 Comments

For poor [workshop from scratch], winter brings the joy of a cold workshop. Since the building is structurally made from tin, warming up the room is difficult.

Naturally, the solution was to construct a homemade wood furnace. The build starts off with an angle grinder being taken to a compressed air tank. After sawing off the top and sanding down the edges, the builder slices out an opening and welds together some rods into a stand for the center. He then proceeds to weld some external frames for the furnace, as well as a chimney stack, some nifty covers joined by hinges, and a fan/temperature regulator to keep the fire going.

Most of the pieces seem to come from scrap metal lying around the workshop, although the degree to which the entire project comes together is quite smooth. Some filter and spray paint do the trick for cleaning up the furnace and making it look less scrappy. The last step? A stack of wooden logs and a blow torch to start the fun. Outside of the furnace, an LCD screen keeps track of the temperature, giving some feedback and control.

The result is perhaps a too effective at warming up the workshop, but the problem sure is solved!

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Hacked Heating Instruments For The DIY Biology Lab

November 12, 2018 by 4 Comments

[Justin] from The Thought Emporium takes on a common molecular biology problem with these homebrew heating instruments for the DIY biology lab.

The action at the molecular biology bench boils down to a few simple tasks: suck stuff, spit stuff, cool stuff, and heat stuff. Pipettes take care of the sucking and spitting, while ice buckets and refrigerators do the cooling. The heating, however, can be problematic; vessels of various sizes need to be accommodated at different, carefully controlled temperatures. It’s not uncommon to see dozens of different incubators, heat blocks, heat plates, and even walk-in environmental chambers in the typical lab, all acquired and maintained at great cost. It’s enough to discourage any would-be biohacker from starting a lab.

[Justin] knew It doesn’t need to be that way, though. So he tackled two common devices:  the incubator and the heating block. The build used as many off-the-shelf components as possible, keeping costs down. The incubator is dead simple: an insulated plastic picnic cooler with a thermostatically controlled reptile heating pad. That proves to be more than serviceable up to 40°, at the high end of what most yeast and bacterial cultures require.

The heat block, used to heat small plastic reaction vessels called Eppendorf tubes, was a little more complicated to construct. Scrap heat sinks yielded aluminum stock, which despite going through a bit of a machinist’s nightmare on the drill press came out surprisingly nice. Heat for the block is provided by a commercial Peltier module and controller; it looks good up to 42°, a common temperature for heat-shocking yeast and tricking them into taking up foreign DNA.

We’re impressed with how cheaply [Justin] was able to throw together these instruments, and we’re looking forward to seeing how he utilizes them. He’s already biohacked himself, so seeing what happens to yeast and bacteria in his DIY lab should be interesting.

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