Pencil drawing of the 21energy Shield

Industrial Space heater Unknown

21energy Shield

A loud, workshop-style 'industrial' bitcoin heater from 21energy: 1.1–2 kW of heat for spaces up to 80 m² with up to 24 TH/s of older, less efficient mining hardware. Plug-and-play on a 16 A, 230 V socket. Currently sold out at half price.

Best price $694

$28.92 per TH · New · Out of stock at 21energy · excl. tax

50% off (was EUR 1,247.50 excl. VAT)

Reviews from Nostr ↓

Hashrate24 TH/s worst 250 GH/sbest 1.16 PH/s 145th best of 197 (the bar uses a log scale)
Power (stock)2,000 W lowest 11 Whighest 22 kW 135th highest of 199 (the bar uses a log scale)
Efficiency83 J/TH worst 100 J/THbest 8.9 J/TH 192nd best of 195
Earns per kWh$0.018 worst $0.010best $0.171 191st best of 195
Heat output6,824 BTU/h worst 38 BTU/hbest 75,067 BTU/h 135th best of 199 (the bar uses a log scale)
Noise50–70 dB worst 76 dBbest 25 dB 52nd best of 68
Price per TH$28.92 worst $539.96best $1.82 103rd 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
21energy Ships from Austria · Maker's own shop 50% off (was EUR 1,247.50 excl. VAT) TrustScore 4.8 out of 5, 1,194 reviews New Out of stock €624 excl. tax $694 $28.92 4 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

Brand21energy
ModelShield
SKUH-21-SHD-XXXXXXX-N-X
TypeSpace heater · Industrial
Form factor—
CoolingAir
Production statusUnknown *
Launch date—
Hashrate24 TH/s
Power consumption (stock)2,000 W
Mining efficiency83 J/TH *
ASIC chipNot known yet
Heat output6,824 BTU/h
Input voltage230 V, 16 A
Frequency—
Net dimensions (W × D × H)—
Net weight—
Noise50–70 dB
Operating temperature—
Area heated80 m² (maker's claim)
Colours—
Company based inAustria
Made inAustria

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

Features

  • Plug and play
  • LAN port
  • 16 A 230 V connection
  • Affordable spare parts
  • 1-year warranty
  • CE compliant

Reviews

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Sources and data notes

Not yet confirmed from the maker's own documents: form factor; dimensions; weight; operating temperature; production status; launch date; efficiency (computed: 2,000 W / 24 TH/s; the page's 'up to 75 J/TH' is a best-case claim).

Spotted a mistake? Let us know.