Using A Bitcoin Miner As A Heater

This article presents the offset-hand experiences of TechEngineer, an at-dwelling house bitcoin miner using heat exhaust from mining machines to warm their firm. Complete with photos, performance data, and some step-by-step instructions, this guide is the perfect beginner resource for miners interested in productive uses for the heat their machines create.

Background and Inspiration

The date was November 29th, 2017. I was driving in my truck and heard on the radio that the toll of
Bitcoin had passed $x,000
for the first time in its history. That is the day that my journey began down the long and heady
rabbit hole of Bitcoin. I was intrigued and instantly fatigued to the technology backside the well-nigh powerful decentralized computer the world had e’er seen.
I wanted to mine Bitcoin.

‍I attempted to buy my first miner, an
Antminer S9 for a price of nearly $four,000
in the beginning of December 2017. The price of Bitcoin was skyrocketing at the fourth dimension and so was the profitability of Bitcoin mining. At that place was a
45 twenty-four hour period lead time on the miner
I had paid for. During that 45 days I watched the price of Bitcoin peak and fall and in my
FOMO
I purchased a pocket-sized mining contract. I learned that the incredible profitability of
Bitcoin mining during a bull run
does not last long. Network difficulty lags, simply catches and surpasses cost, then when price crashes, profitability drops off a ledge.

My
mining contract
that was producing plenty of Bitcoin at first, was now making nothing equally the toll of electricity passed the price of mined Bitcoin. My miner never came and I was refunded the coin. Lessons were learned and I realized I was non quite set up to take the plunge into mining Bitcoin.
The risks and barriers to entry were high, even for an interested and technical person.

‍Fast forward to 2021, I had a newly inspired interest in Bitcoin based on the political and financial direction the world was going. I knew
the earth needed Bitcoin
more than ever and I wanted to practice my part as a citizen of the developing Bitcoin world – helping secure and protect the network past
running my ain node and miners.

With the noesis that
Bitcoin mining at home
can be a costly attempt with sometimes large, but potentially slim profit margins, I knew I needed to shift the profitability equation. I realized that if I could utilise the
waste heat from the miners to rut my business firm, then the cost-do good analysis of mining becomes
much more favorable and sustainable. Decentralizing Bitcoin mining became too important to me and I had to
learn to Mine 4 Estrus.

Concept and Pattern

As a long-time DIY’er and a engineering science-loving engineer, I was excited to solve this
problem of mining heat frazzle. I knew I wanted to use the oestrus from the miners,
but how?
The simple reply is: put the miner in a room and
use it every bit a space heater.‍

In theory, this does piece of work. But there are still
a couple of problems. Starting time, the
noise: it will be very loud and you volition only heat 1 room (a lot) while not heating the rest of the house. I wanted to somehow tie in to my existing ductwork that already had the optimal airflow through the entire business firm. Second,
sustainability: I also knew that for this to be sustainable in an active house, it had to be
seamless, quiet, robust and automated. In my house, the attic was the optimal location where the furnace already resided and xvi” of insulation would create an
optimum sound bulwark.‍

The showtime step was to put some ideas on the whiteboard.

As the whiteboard sketches evidence,
I devised ii scenarios:
heat requested and oestrus not requested. At this point I had no idea how I would achieve the switch between heating and venting into the cranium, merely at least I had
the idea visualized.

Engineer and Build

Once I had a concept, I at present knew that I needed a container or box that was capable of safely belongings the miners and funneling air through them. Since this was a proof of concept and test, I
decided to offset utilise Antminer S9’s
that were a couple generations old in 2021 and thus
relatively inexpensive. I settled on a box that would hold 3 Antminer S9’s, figuring that
~4500 watts running 24/vii would exist plenty
to at to the lowest degree mostly heat my house.

After searching for pre-made metallic boxes effectually this size I needed and non finding them, I ended upward edifice the box myself. I took some measurements, and sketched out a box. The measurements of the box are xvi.75” broad X 10.5” tall X 17” long.
I used plywood, just wanted to get in a bit more than like a duct box then I lined information technology with sail metal.
This would brand the box heat and fire retardant. I as well fastened some
hinges
to the pinnacle to make a
elementary and secure lid.

‍For the ductwork,
I settled on viii” to keep ducting small plenty to handle in the attic and a x” would non have fit in my junction duct. I had calculated an viii.66” minimum duct size, but I knew I would be able to
offset some loss in airflow
size with a more than powerful fan. (In hindsight, more than airflow volume would have been better.)

After sourcing ducting parts at the local hardware store, I plant a 14 10 6” register box that would
serve as the air intake and outlet attachments
to the box and ducting. I cut holes in the ends of the box and attached the registers. I attached an
8” inline duct fan
and some
8” flex ducting.
Then I demote tested my pattern.
Information technology was working!

The next footstep was to figure out the all-time way to tie it into
my existing HVAC system
while doing the
least amount of permanent changes
to information technology. I decided to connect the output of the Bitcoin miner heater to the intake register box. This way, when the furnace fan was on it would pull the hot air directly into the intake, but when the fan was off the miner could
still dump hot air into the house, if need exist.

Now that I had a box and ducting, the next step was to build the full system in the attic. I
ducted in an intake to the house
and
the exhaust to the intake of the furnace. One of the first things I realized is that I
needed a more powerful exhaust fan
than the original 300 CFM inline fan. An
upgraded 740 CFM fan
helped information technology run much cooler, and the miner fans did non have to spin up every bit fast.

I used and tested the system in a
manual fashion for several weeks. My proof of concept was working. Although the
go out temp at vents
was nowhere almost the temp the furnace would output, I was not concerned. The purpose was for the miners to run all the time, and so
slow and steady heating was the name of the game.

BraiinsOS+ became my firmware of choice during this time, as the
visibility into the miner operations
is superior. I was also impressed with the firmware’s ability to
dynamically scale hashrate based on temperature events. In my case, I could dynamically scale the miners down when temps were higher than normal (like a hotter solar day) and I did non need equally much heat. At the time I also thought of the possibility of
scaling hashrate up and downwardly based on external temperature
or smart home events, only integrations like that had not been built (yet)!

Command and Automation

Once I had enough
data to prove the heater was heating
my house, I needed to
automate the transition from estrus to no heat. I decided to use some
duct splitters and dampers. Dampers are unremarkably used to command airflow to different parts of a house. They tin can exist activated to change position with
a 24V signal from a thermostat. In my example, the two dampers to and from the cranium are unpowered open / ability close, while the two dampers for the business firm are power open / unpowered shut.

Effectively, when no rut is chosen for,
dampers are in their unpowered land
and airflow directs in and out the attic. When rut is chosen for,
the thermostat powers all four dampers, they change position and direct airflow in and out of the house.

In order to
tie in to the thermostat
so that information technology heats or exhausts
on demand from heating needs, I wired my
Ecobee thermostat
direct to them equally a “stage one” heater.

At present there would substantially be
three different modes:

• Heat Off = Open up dampers to/from attic. Master HVAC fan off.
• Stage one heat On = Open dampers to/from house. Furnace fan on. Furnace heater off.
• Stage 2 heat On = Open dampers to/from firm. Furnace fan on. Furnace heater on.

With this setup, I was now able to
ready my thermostat to whatever temperature I wanted, and the
arrangement would automatically switch dampers
to control the miner oestrus flow into or out of the house. Also, in the event of farthermost cold, “stage 2” was still available to kick on the main furnace heater and rut equally normal.
The Bitcoin miner heater was now thermostatically controlled.‍

The final pace in the build was to
add together some safety features. An attic tin can be a hot, dry place, and when dealing with electronics in this surround, it’due south important to
proceed fire safety in mind

(especially in a residential setting).

I already had a full smart domicile setup using a
Hubitat smart home controller, so I knew that I could add some sensors and controllers to assistance automate this procedure equally well. I found
a 240V Zwave controller and a Zwave smoke warning
that would fit my needs nicely. I wired in the 240V smart controller to have total command of the miner excursion from the Hubitat. I put the Zwave smoke detector in the box. I had another smart switch connected to the inline exhaust fan, as well as temp sensors inside and outside of the box. On top of that,
the Hubitat is besides able to control the Ecobee thermostat
and shut downwards the furnace as needed.

‍With all of the in a higher place resources, I congenital an automation that does the following:‍

‍If smoke or loftier temperature are detected, shut down miners, exhaust fan and furnace.
Also, this outcome
triggers the house alarm siren and turns on lights
in the firm to wake everyone upward, likewise every bit
sending a notification to my telephone. Theoretically since all airflow through the box is stopped, if there were a small fire it would be smothered due to lack of oxygen,
or at least minimized due to cutting power. Just to exist sure, everyone in the house is notified then that the problem can be investigated.

‍Finally, my Bitcoin miner heater was complete
– thermostatically controlled and heating my house.

Hither is the concluding layout:

Data and Analysis

Over the next few months,
I collected information from my thermostat and smart home sensors
to determine the
effectiveness
and
efficiency
of the system. The graph below shows that
the system was able to maintain the gear up bespeak temperature
throughout varying outdoor temperature ranges.

Total runtime of Phase 2 (master heater) was minimized to
1.i hours for the entire calendar month, while the Bitcoin heater actively pumped heat into the house
46% of the month.

‍How efficient was the system?
The table beneath shows some toll
comparisons over a 2-month period
compared with the previous year. This data was compiled in February 2022 when the USD equivalent BTC price was approximately $43,000. Go along in mind that the cost and difficulty of Bitcoin mining varies greatly. Also, this is
while mining with iii of the least efficient ASIC miners in 2022, Antminer S9’south. New miners are approximately 3-4 times more efficient, so numbers would exist much amend.

Conclusion

Mining 4 Heat is an constructive way to
motility the profitability equation in favor of small mining operations. Since edifice this organization I have begun
developing an immersion based Bitcoin water heating arrangement
that has applications in heating homes, pools, water heaters, greenhouses, and more.
These systems are in their infancy, but with the innovation of the Bitcoin community, mining will stay highly
decentralized through deeper integration into heating applications.

‍

This article was written for the Braiins blog by TechEngineer. Follow his mining journey on Twitter by following

@TechEngineer21
, and see a full video walkthrough of his abode mining heating arrangement on YouTube

here
.

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