ESP8266 Keeps Tabs On Wood Stove Temperature

December 15, 2024 by Tom Nardi 37 Comments

Wood heat offers unique advantages compared to more modern heating systems, especially in remote areas. But it also comes with its own challenges, namely, keeping the fire going at the optimum temperature. If it’s too cold you risk buildup in the chimney, but if you’ve got it stoked up more than necessary, you’ll end up burning through your wood faster.

To keep the fire in that sweet spot, [Jay] decided to put an ESP8266 and a thermocouple to work. Now, this might seem like an easy enough job at first, but things are complicated by the fact that the flue temperature above the stove lags considerably behind the temperature inside the stove. There’s also the fact that the top of the chimney will end up being much colder than the bottom.

Mounting the thermocouple in the flue pipe.

In an effort to get a more complete view of what’s happening, [Jay] plans on putting at least two thermocouples in the chimney. But as getting on the roof in December isn’t his idea of fun, for now, he’s starting with the lower one that’s mounted right above the stove. He popped a hole in the pipe to screw in a standard K-type probe, and tapped it a few times with the welder to make sure it wasn’t going anywhere.

From there, the thermocople connects to a MAX6675 amplifier, and then to the WeMos D1 Mini development board that’s been flashed with ESPHome. [Jay] provides the configuration file that will get the flue temperature into Home Assistant, as well as set up notifications for various temperature events. The whole thing goes into a 3D printed box, and gets mounted behind the stove.

This project is a great example on how you can get some real-world data into Home Assistant quickly and easily. In the future, [Jay] not only wants to add that second thermocouple, but also look into manipulating the stove’s air controls with a linear actuator. Here’s hoping we get an update as his woodstove learns some new tricks.

Automating The Most Analog Of HVAC Equipment

February 20, 2023 by Bryan Cockfield 35 Comments

Burning wood, while not a perfect heating solution, has a number of advantages over more modern heating appliances. It’s a renewable resource, doesn’t add carbon to the atmosphere over geologic time scales like fossil fuels do, can be harvested locally using simple tools, and it doesn’t require any modern infrastructure to support it. That being said, wood stoves aren’t something that are very high-tech and don’t lend themselves particularly well to automation as a result, at least with the exception of this wood stove from [jotulf45v2].

While this doesn’t automate the loading or direct control of a modern pellet stove, it does help [jotulf45v2] know when the best times are for loading more wood into the stove and helps keep the stove in the right temperature range to avoid the dangerous formation of creosote on the inside of his chimney caused by low temperature burns. Two temperature sensors, one on the stovetop and the other on the stove pipe, monitor the stove exhaust temperature. They feed data to a Node-RED system running on a Raspberry Pi which automatically notifies the user by text message when certain stove temperatures are reached.

For anyone heating with wood, tools like this are indispensable to help avoid spending an otherwise unnecessary amount of time getting a fire up to temperature quickly without over-firing the stove. Modern pellet stoves have some more modern conveniences like this built in, but many of the perks of using cord wood are lost with these devices. There are plenty of other ways to heat with wood too; take a look at this custom wood boiler which serves as a hot water heater.

Simple Wood-Fired Water Heater Is Surprisingly Effective

February 8, 2023 by Lewin Day 55 Comments

These days, humans have gotten all fancy-schmancy with their gas and electric water heaters. Heck, some are even using heat pumps to do the work as efficiently as possible. [HowToLou] got back to basics instead, with his simple wood-fired water heater design.

The design is straightforward, featuring 100ft of quarter-inch copper tubing wrapped directly around a steel barrel. Room-temperature water is fed into the tubing via a garden hose, and comes out much hotter, thanks to a fire burning away in the barrel stove of [Lou’s] own construction.

For an input water temperature of 41 F, the output reaches 105 F at a flow rate of 0.67 gallons per minute. By [Lou]’s calculations, that’s a heat transfer to the water of roughly 21,000 BTU per hour. [Lou] achieved this with just $55 worth of copper tubing, and he notes that simply doubling up the tubing would increase the heat transfer to the water even further.

If you’re looking for a hot shower from your outdoor wood stove, a build like this might be just the ticket. With the stove burning hot and your hose as a water supply, you could experience the joy of the hot water while you’re standing in the snow outside. We’ve seen [Lou]’s work before, too. Video after the break.

Continue reading “Simple Wood-Fired Water Heater Is Surprisingly Effective” →

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

January 30, 2021 by Jenny List 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!

Continue reading “A Heat Reclaimer For Your Woodstove; The One Thing It’s Not Is Cool” →

Wood Stove Runs On Arduino Power

March 6, 2016 by Elliot Williams 15 Comments

Ahh, sweet scope creep! Usually it’s the death of a nice, simple little hack. But once in a hundred times, a small hack doesn’t get buried under the extra features, but instead absorbs them in stride and blossoms into a beautiful system. [rockfishon]’s Arduino-powered wood stove controller is one of these beautiful exceptions. (OK, we’d admit that it could use a fancier faceplate.)

He started off simply enough, wanting to connect a thermocouple to an Arduino, read out the value, and issue an alarm when the temperature got too high. But who could stop there? Just one air-baffle servo away from a closed-loop heating control system? So [rockfishon] added a display and a few more buttons and has a system that will keep his wood-burning stove running at exactly the right temperature, even overnight when nobody’s around to tend it. As a bonus, everything is logged for later analysis.

The code is relatively straightforward, and can be found in this Gist. If you’d like to build your own, you’ll need an Arduino Mega and can then get the control board made for you at OSHPark. Judging from the comments on the Hackaday.io project page, a couple people have already tried this out. We’ve seen other wood-stove monitoring hacks before, but this is the first we’ve seen that closes the control loop. Very cool.

A Wireless Wood Stove Monitor

February 8, 2016 by Kristina Panos 25 Comments

[Michel] has a wood stove in his basement for extra heat in the winter. While this is a nice secondary heat source, he has creosote buildup in the chimney to worry about. [Michel] knows that by carefully monitoring the temperature of the gases in the chimney, he can hit the sweet spot where his fire burns hot enough to keep the creosote under control and cool enough that it doesn’t burn down the house. To that end, he built a wireless wood stove monitor.

The first version he built involved an annoying 20 foot run between the basement and living room. Also, the thermocouple was mounted on the surface and made poor contact with the chimney. Wood Stove Monitor 2.0 uses a probe thermometer on an Exhaust Gas Temperature (EGT) thermocouple to measure the temperatures. The intel is fed to a thermocouple amplifier to provide a cold-compensation reference. This is shielded so that radiant heat from the stove doesn’t compromise the readings. An nRF24L01+ in the basement monitoring station communicates with another module sitting in the living room display so [Michel] can easily find out what’s going on downstairs. When it’s all said and done, this monitor will be part of a bigger project to monitor power all over the house.

Interested in using a wood stove to help heat your house? Why not build your own?

This Little Piggy Stayed Home And Became A Stove

February 25, 2014 by James Hobson 11 Comments

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This little piggy probably should have gone to the market. Instead, its become an extremely decorative, and cute, wood burning stove!

After being inspired by a similar Instructable that guides you through the creation of a wood stove using an expired gas cylinder, [Ruudvande] had to try it himself. The problem was — he didn’t have a gas tank. Luckily for him, he found someone who did, but as it turned out, they wanted to turn it into a barbecue! So, slightly sidetracked, he built them a barbecue using the center of the cylinder, and got to keep the ends and enough steel to make Mr. Piggy himself.

Almost the entire wood burning stove is made of scrap bits and pieces of steel, and various pieces of mounting hardware. Armed with just a MIG welder, [Ruudvande] welded it together all by hand, and we think it turned out great! He’s not quite happy with it yet though and plans to upgrade the chimney, put a larger grill inside, paint it, and even add a glass window to the door.