Pencil drawing of the Altair Technology BitChimney Space Heater (v2)

Space heater Floor standing Unknown

Altair Technology BitChimney Space Heater (v2)

Altair's aluminium BitChimney holds one Antminer hashboard (S19k Pro, S21 or T21) with an APW3++ supply and LuxOS firmware. Two preset modes run at 750 W or up to 1,000 W, giving 31–53 TH/s depending on the board, at about 49–56 dB. Every version was out of stock on 2026-11-04.

Best price $549

$14.45 per TH · New · Out of stock at Altair Technology

S19k Pro version (S21 $999, T21 $1,099, DIY kit $349)

Note from 4 Nov 2026.

Reviews from Nostr ↓

Hashrate38 TH/s worst 250 GH/sbest 1.16 PH/s 140th best of 197 (the bar uses a log scale)
Power (stock)950 W lowest 11 Whighest 22 kW 150th highest of 199 (the bar uses a log scale)
Efficiency25 J/TH worst 100 J/THbest 8.9 J/TH 148th best of 195
Earns per kWh$0.061 worst $0.010best $0.171 148th best of 195
Heat output3,242 BTU/h worst 38 BTU/hbest 75,067 BTU/h 150th best of 199 (the bar uses a log scale)
Noise49–56 dB worst 76 dBbest 25 dB 45th best of 68
Price per TH$14.45 worst $539.96best $1.82 78th best of 156 (the bar uses a log scale)

Where to buy

Store Trustpilot Condition Availability Listed price In your currency Per TH Checked Link
Altair Technology Ships from United States S19k Pro version (S21 $999, T21 $1,099, DIY kit $349) These notes are from 4 Nov 2026. Price and stock were checked since. TrustScore 4.7 out of 5, 623 reviews New Out of stock $549 $549 $14.45 12 Nov 2026 Visit

Prices as listed on each store's page on the date shown, without shipping. Prices marked excl. tax leave out VAT or sales tax, and others may too. Per TH uses the hashrate of the unit each store sells. Converted at ECB rates of 11 Nov 2026. Trustpilot scores are for the store, not the device. Each store's name opens its page, with everything it sells and its reviews.

Heat, running cost and sats

Heat per day
—
Electricity per day
—
Mining earns per day*
—
Net cost per day
—
Net cost per kWh of heat
—
Solo: chance of a block per year
—
Earns per kWh, on 3-month averages
—
Payback
—

*What a pool would pay on average at today's difficulty, block reward and bitcoin price, before pool fees. Solo miners usually earn nothing, and very rarely a whole block. A plain electric heater turns the same electricity into the same heat, so the mining income is what makes the difference.

Payback is how long the bitcoin a device earns takes to add up to its price. It leaves out electricity, which buys the heat: compare earnings per kWh with your electricity price to see whether mining alone covers it. It uses the average of the last 3 months, to 12 Nov 2026: bitcoin at $79,558, 969 EH/s on the network and 3.15 BTC a block, less a 2% pool fee, for the hours you set. It cuts the block subsidy in half at each halving, the next around Apr 2028, and otherwise assumes those carry on unchanged, which they won't. Income at today's difficulty and price is about 17% below that average. Hashrate usually rises, though miners that stop paying after a halving may switch off, which leaves more for the rest. How we work it out.

Specifications

BrandAltair Technology
ModelBitChimney Space Heater (v2)
SKUATBCHMV2 (ATBCHMV2KP S19k Pro, ATBCHMV2S21 S21, ATBCHMV2T21 T21, ATBCHM DIY kit)
TypeSpace heater · Home
Form factorFloor standing
CoolingAir
Production statusUnknown *
Launch date—
Hashrate38 TH/s *
Power consumption (stock)950 W *
Mining efficiency25 J/TH
ASIC chipBitmain BM1366 × 77 (reported by an independent source); BM1368 in some versions
Miner inside1 x Bitmain Antminer hashboard: S19k Pro, S21 or T21 depending on version
Heat output3,242 BTU/h
Input voltage110–240 V AC (APW3++)
Frequency—
Net dimensions (W × D × H)610 × 203 × 457 mm (24 × 8 × 18 in) *
Net weight12.2 kg (26.9 lb)
Noise49–56 dB *
Operating temperature—
Area heatedAbout 6.3–19 m² (our estimate)
Colours—
Company based inUnited States
Made in—

* Not confirmed by the maker's own documents yet.

Hashrate versions

VersionHashratePowerEfficiency
BitChimney S19k Pro (High Power mode) ATBCHMV2KP38 TH/s950 W25 J/TH
BitChimney S21 (High Power mode) ATBCHMV2S2153 TH/s1,000 W19 J/TH
BitChimney T21 (High Power mode) ATBCHMV2T2147 TH/s1,000 W21 J/TH

Heat modes

ModeHashratePowerHeat
Normal (S19k Pro)31 TH/s750 W2,559 BTU/h
High Power (S19k Pro)38 TH/s950 W3,242 BTU/h
Normal (S21)40 TH/s750 W2,559 BTU/h
High Power (S21)53 TH/s1,000 W3,412 BTU/h
Normal (T21)34 TH/s750 W2,559 BTU/h
High Power (T21)47 TH/s1,000 W3,412 BTU/h

Features

  • Single Antminer hashboard: S19k Pro, S21 or T21
  • DIY kit without hashboard available
  • APW3++ PSU included (110–240 V)
  • LuxOS firmware with thermal management and tuning presets
  • Wi-Fi via included Vonets bridge
  • Aluminium body
  • 10 A fuse on power entry
  • Ships fully assembled
  • No UL/ETL/CE/CSA certification (per FAQ)

Reviews

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Sources and data notes

Chip by version: BitChimney S21 (High Power mode): BM1368 × 108 (reported); BitChimney T21 (High Power mode): BM1368 × 108 (reported). See the chips page.

Not yet confirmed from the maker's own documents: colours; production status (all variants out of stock); launch date; where it's made; hashrate and power nominal (S19k Pro version in High Power mode chosen; the page's overall range is 500-1,000 W at the wall); dimensions (24 x 18 x 8 in from the store's 'Additional information' table, which may be the shipping size); noise (49/56 dB per mode from the variant descriptions; the FAQ says about 53 dB at 3 ft on stock settings).

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