Mining Rigs as Heaters – If the Glove Fits, Why Not?
Crypto mining, when scaled to large capacities, requires lots of power. And with such electrical power requirements, comes residual heat. This is why cooling is the second most important aspect of crypto-mining hardware.
But what if we can instead harness that heat directly for something else to boost the rig’s overall efficiency? In this article, we shall discuss the potential of mining rigs as heaters, and whether they could significantly offset heating costs for bigger net profitability.
Theoretical Benefits of Mining Rigs as Heaters
Turns an inefficiency metric into something useful – heat output is often regarded as a waste byproduct of any computer. But with mining rigs as heaters, this effectively adds to the overall usability of the system. Precise temperature control is still required, of course, otherwise excessive heat buildup can still lead to eventual component failure.
Replaces hardware required for heating – when outfitting a crypto mining rig for heating, the additional investment needed to purchase dedicated heating hardware may no longer be necessary. The saved costs can then be recirculated to the rig for additional improvements and modifications.
Profitable while reducing heating costs – heat dissipation traditionally adds to the cost of stabilizing the performance of any crypto mining rig. This is mainly in the form of reduced external hardware for cooling. Again, precise control is required, as the heat generated by the GPU would usually still be sufficiently higher than the practical heat transferred to the room.
If not profitable, at least negates any energy costs – same principle as the previous, but with cost neutrality in mind. If the heating requirements are too high, or the profitability is not expected to be high (at that point in time), you can at least aim to effectively get back what the electricity cost would have been using traditional hardware.
How Calculations for Heaters Generally Work
When planning to install heating hardware in rooms, users typically start with calculating the number of watts needed per target unit area. First, you need to know the total area of the room in feet, and then multiply it by 10. That should give you a mean value of the wattage needed, thereby also knowing which product to use.
For example, a 20×20 feet room will have an area of 400 square feet. Therefore, the wattage necessary for the heating hardware of this room is 4000 watts. Reversely, a 1500-watt heater will be able to efficiently heat a maximum area of about 150 square feet (divide by 10).
This is just a rule of thumb, though. Because for one thing, this does not consider the level of insulation a room has by default. Good insulation can reduce the wattage needed, while sub-optimal ones might require higher values. If the height of the room is significantly higher than typical rooms in your country, you may also have to add that to your equation.
Thankfully, you can easily find reliable-ish room heating calculators online. Not only do these consider room height and insulation level, but calculations in meters might also be available.
Operational Considerations when using Mining Rigs as Heaters
With these elements in mind, we would either need the total wattage output of your mining rig, and the estimated heating requirements of your home. There are several rather obvious caveats, however:
- Dedicated heating hardware converts almost all of its electricity to heat. For mining rigs, heat is only a byproduct. Most of the energy is used in computational work, with most of the heat dissipated via convection (fans). Therefore the amount of effective heat output is significantly smaller.
- At least according to this simple guide, a safe guideline is to consider only 40% of the total energy output of your mining rig. So, if your GPU array plus system power reports 1000 watts, consider the rig as producing only 400 watts for “proper” heating.
- Because of this, you would often find that mining rigs require bigger spaces to work with if used with the express intent of doubling as space heaters. Strategic consideration for its location in a room would then be an important priority.
For example, a mining rig using six GPUs would typically occupy a space of 1.1×1.1×2.1 feet, which already includes the motherboard and power supply. If the GPUs used are, let’s say, RTX 3070s, then we can estimate that it would eat up 1700 watts, or around 680 watts of effective room heating.
Scale that up to at least one more complete rig, and you already have a decent theoretical mining rig space heater that can warm up a 136 square feet room (680 watts x2). Since its size allows it to be comfortably set on a table, you’d probably only need one corner of your room to place both rigs.
Mining Rig Heaters Vs. Commercial Heaters
According to this older article, your typical $30-$35 1500-watt space heater, when used at least eight hours per day at $0.13 kWh, will require $48.00 per month of operation. Using the same twelve-RTX-3070 mining rig above, we would need 3400 watts of electrical energy to achieve similar-ish 1360 watts of heating. That results in $107 per month of operation if also equated at $0.13 per kWh.
Needless to say, if used purely for heating, the RTX 3070 rig loses out. But, if you used this same setup sometime during the height of the second crypto mining boom (2021), then the cost is completely negated. Twelve RTX 3070 crunching at about 60-65 MH/s each GPU would net you at minimum an equivalent of $2200 in Ethereum.
If you don’t mind the fact that mining rigs generally require larger dedicated spaces, then this would be the best theoretical option. Especially if to be used as a simple space heater, since all you need to do is strategically place them in the room where the general airflow of its cooling system would spread evenly. For more sophisticated central heating systems, you also need to consider how to hook up the mining rig’s heatsink safely. Something like this old mining rig heater guide should give you an idea of the additional requirements for such a system.
Then again, starting in late 2022, the idea might no longer be feasible with the crypto crash and Ethereum’s change to proof-of-stake. Even if you aim for simple cost parity by mining a smaller coin that is widely accepted on crypto casinos like CoinSlotty, you’d still have to deal with purchasing the rig components. GPUs may have returned to normal prices now, but if you are not a crypto mining hobbyist, there would be little incentive to beat the good ol’ classic $30 1500-watt space heater.
Commercial Mining Rig Space Heaters?
Some of you may then ask… why not use Bitcoin ASIC miners as space heaters? Despite the exorbitant cost, surely such a rig would still be able to pay back heating costs and more. Well, because commercial mining heaters have recently just begun entering the tech market.
Heatbit, touted as the world’s very first commercial (dedicated) Bitcoin-mining space heater, debuted sometime in late 2022. It is advertised as being able to heat up to 500 square feet of space, while mining Bitcoins on the side. As of this article’s writing, Bitcoin is at more or less $20,000 per coin. So the Heatbit could theoretically heat your home while earning back $30 in cryptocurrency per month. Not exactly the ideal cost-payback machine, considering its retail price of $1,200. But, it’s a start.
Instead of originally spending about $10,000 for something like an Antminer S19J Pro, building a custom fan for it (and spending more), you instead comfortably spend ten times less, for something that is actually designed to look and feel like an ordinary space heater.
Granted, it won’t exactly negate your heating costs. But if enough demand for such a product is generated, then we may witness later a complete market for commercial mining heaters. As these products would inevitably be streamlined to earn money on the manufacturer’s side, any custom-built ASIC miner for heating would easily lose out in efficiency.
Conclusion: Are Mining Rig Heaters Worth it?
From an investment perspective, no. Mining rig heaters are not financially worth investing. Though they are exciting to do as a fun experiment, they are not profitable at this point in time. At best, you may only be able to negate the cost of electricity, but not the hardware and effort required to build the rig.
However, if you are referring to (upcoming) commercial mining heaters, then they may have a potential future. If you are not into crypto mining as a hobby, you can purchase these items directly and use them on the spot. No need for complicated building instructions, or computer hardware know-how to set these things up.
Plus, you even have something that can aesthetically fit as room décor!