Mining Heat Recovery Calculator
Calculate the heating value and cost savings from capturing waste heat produced by crypto mining equipment.
About this calculator
Every watt a mining ASIC or GPU rig draws from the wall eventually leaves as heat — there's no other place for it to go — so this calculator starts from a strict thermodynamic conversion (1 kW = 3,412 BTU/hr) to find the total heat output of your mining power draw, then discounts it by a recovery efficiency percentage to reflect real-world losses in ducting or heat exchangers (the calculator's own guidance: roughly 50-70% for simple air ducting, 80-95% for immersion cooling). That recoverable heat is valued two ways. For space heating, it's converted to therms (100,000 BTU each) and multiplied out across the heating season you specify, then priced against your local fuel cost to get monthly and annual savings — this only counts during the months you say you actually need heat.
For domestic hot water, it computes the BTUs needed to raise your stated daily gallons from inlet to target temperature (using water's exact 8.33 BTU per gallon per °F specific heat) and checks whether your recoverable heat can cover it, reporting what percentage of capacity that represents; water heating savings are calculated year-round since hot water is needed in every season, unlike space heat. The two savings streams are then summed into a total annual figure. One simplification to know: the model assumes the recovered heat is fully usable whenever it's produced and doesn't account for mismatches between when miners run and when heat demand actually occurs, nor for equipment or installation costs of the heat-recovery system itself.
Inputs
Results
Total annual savings ($)
$4,213.70
How to Use This Calculator
- Enter the total mining farm power consumption in kW.
- Set the heat recovery efficiency percentage and the local heating fuel cost per therm.
- Enter the heating season length in months, plus your daily hot water usage and cold/target water temperatures.
- Review the annual heating and water heating cost offsets from recovered mining heat.
- Use this to justify building mining in locations with high heating demands.
How the result changes with Heating fuel cost ($/therm)
| Heating fuel cost ($/therm) | Total annual savings ($) |
|---|---|
| 0.6 | $2,106.85 |
| 0.9 | $3,160.28 |
| 1.8 | $6,320.55 |
| 3 | $10,534.25 |
What each input means
- Total mining power (kW)
- Total power consumed by mining equipment in kilowatts (e.g., 10 miners at 3,250W = 32.5 kW).
- Heat recovery efficiency (%)
- Percentage of waste heat successfully captured. Air ducting: 50-70%. Immersion cooling: 80-95%.
- Heating fuel cost ($/therm)
- Cost of the fuel being replaced (natural gas ~$1.00-$1.50/therm, propane ~$2.50/therm, oil ~$3.00/therm).
- Heating season (months)
- Number of months per year where space heating is needed.
- Hot water usage (gal/day)
- Daily hot water consumption in gallons. Average household: 50-80 gal/day.
- Cold water temp (°F)
- Temperature of incoming cold water.
- Target water temp (°F)
- Desired hot water temperature. Standard residential: 120°F.
What each result means
- Total annual savings ($)
- Combined heating and hot water fuel cost savings per year.
- Total heat output (BTU/hr)
- Total heat produced by mining equipment.
- Recoverable heat (BTU/hr)
- Heat that can actually be captured and used, based on your recovery efficiency.
- Monthly heating savings ($)
- Monthly fuel savings during the heating season.
- Annual heating savings ($)
- Total space heating fuel savings per year.
- Annual water heating savings ($)
- Fuel savings from pre-heating or fully heating domestic water year-round.
- Equivalent heated area (sq ft)
- Approximate floor area that could be heated by the recovered heat.
- Water heating capacity used (%)
- Percentage of recoverable heat consumed by water heating. Under 100% means surplus heat is available.
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersTotal mining power (kW) = 32.5, Heat recovery efficiency (%) = 70, Heating fuel cost ($/therm) = 1.2, Heating season (months) = 6 = 7 input(s) provided
- Calculate Total annual savingsTotal annual savings = annualHeatingFuelSavings + annualWaterHeatingSavings4213.7 = $4,213.7
- Calculate Total heat outputTotal heat output = totalMiningPowerKw * 1000 * 3.412110890 = 110890
- Calculate Recoverable heatRecoverable heat = totalBtuPerHour * (heatRecoveryEfficiency / 100)77623 = 77623
Engine last updated . Checked against 3 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why does space heating savings depend on the heating season length, but water heating savings don't?
Space heating savings only count during the months you say you actually need heat (Heating season months), since recovered heat has no space-heating value once the season ends. Water heating is calculated year-round instead, because a household needs hot water every day of the year regardless of outdoor temperature.
How does the calculator decide whether recovered heat can fully cover water heating demand?
It computes the BTUs needed daily to raise your specified gallons of water from inlet to target temperature (using water's fixed 8.33 BTU per gallon per °F), divides that by 24 to get an hourly rate, and compares it against your recoverable BTU/hr. The result is reported as water heating capacity used — under 100% means your recovered heat fully covers hot water needs with surplus left over, while it's capped at 100% even if theoretical demand is higher.
What does the heat recovery efficiency percentage actually represent?
It's the share of the miners' total heat output that your ducting or heat exchanger setup can actually capture and deliver, rather than losing to duct leakage, uninsulated runs, or exchanger inefficiency. The calculator's own guidance suggests roughly 50-70% for simple air ducting and 80-95% for immersion cooling, since immersion systems transfer heat directly into a liquid loop with far fewer losses.
Does this calculator account for the cost of installing a heat recovery system?
No — it only models the fuel-cost savings from the heat you recover, not the capital or installation cost of ducting, heat exchangers, or immersion infrastructure needed to capture it. It also assumes all recovered heat is usable exactly when it's produced, without checking whether your miners' run schedule lines up with when you actually need heat.
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