Description
L7 Heater
Most Bitcoin space heaters mine SHA-256. This one mines Scrypt. The L7 Heater – Pivotal Edition is a dual-voltage space heater conversion built on the Bitmain Antminer L7 — pushing ~3.5 GH/s of Scrypt hash rate at ~1,300W while warming a medium-sized room with ~4,434 BTU/hr. Mine Litecoin and Dogecoin while you heat your home. Diversify your hash rate beyond SHA-256 without adding a second electric bill.We take an Antminer L7, strip it down to two hashboards (downclocked for acoustics and stability), replace all stock fans with quiet 120 mm units, install an internal air deflector for even airflow, apply the Pivotal PSU modification for 110–120V compatibility, and load the latest Vnish firmware pre-tuned for indoor duty. The result is a purpose-built space heater that produces real Scrypt hash rate at residential noise levels. Built by hand in our Quebec workshop. Soak-tested for 24 hours before it ships.
Technical Specifications
| Specification | Value |
|---|---|
| Algorithm | Scrypt (Litecoin / Dogecoin) |
| ASIC Chip | Bitmain BM1485 |
| Hash Rate | ~3.5 GH/s (±10%, profile-dependent) |
| Power Draw | ~1,300W at wall (±10%) |
| Max Power Limit | 1,300W — do not exceed on either voltage |
| Heat Output | ~4,434 BTU/hr |
| Hashboards | 2 (downclocked from 4 for acoustics and thermal stability) |
| Voltage | Dual-voltage: 110–120V AC or 200–240V AC, 50/60 Hz (Pivotal PSU mod) |
| Firmware | Vnish (latest, pre-installed and pre-tuned) |
| Cooling | Arctic P12 Max or equivalent (120 mm, miner + PSU) |
| Airflow | Internal air deflector across both hashboards (Hashboard Airflow Inlet Divider) |
| Networking | Ethernet (RJ45); optional external Wi-Fi adapter |
| PSU | APW12 with Pivotal 110–220V modification + silent fan swap |
| Warranty | 90 days (D-Central conversion and tuning work) |
| Base Platform | Bitmain Antminer L7 (refurbished, Pivotal-converted, 24-hour soak tested) |
Scrypt Mining in a Space Heater: Why Diversify
SHA-256 miners are everywhere. Scrypt hash rate is harder to come by in heater form. The L7 is the highest hash rate Scrypt ASIC Bitmain has produced, and this Pivotal Edition puts ~3.5 GH/s of it on your floor in a form factor designed for living spaces. You mine Litecoin and Dogecoin simultaneously (merged mining), and your pool can auto-convert to Bitcoin if you prefer. The point is optionality: running different algorithms across different machines spreads your exposure and keeps your home mining setup interesting.
If you already run an S19 Space Heater Edition for SHA-256, the L7 Pivotal gives you a second algorithm producing heat in a different room. Two machines, two algorithms, two rooms heated. That is hash rate diversification and home heating in one decision.
The Pivotal Modification
The stock Antminer L7 ships with an APW12 PSU that only runs on 200–240V. Most North American homes have 120V outlets in every room and 240V only at the panel. D-Central’s Pivotal modification converts the APW12 to accept 110–120V input, so you can plug it into any standard outlet. We also swap the PSU fan for a quiet 120 mm unit — because a loud power supply defeats the purpose of a silent heater build.
If you have a 240V circuit available, the Pivotal mod handles that too. Same 1,300W cap, slightly better wall efficiency. The power limit is firmware-locked at 1,300W on both voltages — this is a thermal safety boundary, not a suggestion. The two-hashboard configuration and fan capacity are engineered around this ceiling. Running hotter does not mean mining more; it means shorter component life and thermal faults.
Acoustics & Airflow Engineering
We replace every stock fan on the miner and the PSU with quiet 120 mm units (Arctic P12 Max or equivalent). But quiet fans alone are not enough — airflow path matters. The L7’s four-hashboard chassis has two boards removed, which changes internal air pressure. Our internal air deflector (Hashboard Airflow Inlet Divider) guides intake evenly across both active chains, keeps temperatures balanced, and prevents the sudden fan ramp-ups caused by uneven cooling.
The result: a steady, low-frequency hum instead of the high-pitched whine of an industrial ASIC. Place it in a living room, office, or bedroom. Keep intake and exhaust clear. Soft furnishings and open airflow paths absorb the remaining fan tone. It is not silent — it is an appliance with a fan. Quieter than a window AC unit, louder than a fridge.
Firmware: Vnish, Pre-Tuned for Indoor Duty
Every L7 Pivotal ships with the latest Vnish firmware, configured for residential use. Per-chain monitoring shows you exactly what each hashboard is doing. The power-limit slider is locked at 1,300W max. Autotune handles chip-level tuning automatically, and the watchdog system restarts chains if they stall. Pick the 110–120V profile for the quietest behavior, or use the 200–240V profile for tighter wall efficiency at the same power cap.
Set your pool (LTC/DOGE direct, or auto-convert to BTC through your pool), point it at your preferred stratum, and let it run. For firmware documentation and updates: vnish.group.
What’s Included
- Complete L7 Heater – Pivotal Edition (fully assembled, soak-tested, ready to plug in)
- Pivotal-modified APW12 PSU with silent 120 mm fan swap (110–240V compatible)
- Quiet 120 mm fan set installed on the miner
- Internal air deflector (Hashboard Airflow Inlet Divider)
- Vnish firmware pre-installed and pre-tuned
- Quick-start instructions
Heat Coverage Guide
| Room Size | Coverage at ~4,434 BTU/hr | Notes |
|---|---|---|
| 100–200 sq ft | Primary heat source | Bedrooms, home offices, dens |
| 200–350 sq ft | Significant supplemental heat | Living rooms, open-plan areas (with insulation) |
| 350+ sq ft | Supplemental heat only | Pair with a second heater or central heating |
Coverage depends on insulation, ceiling height, and outdoor temperature. A well-insulated Canadian home holds heat better — an unfinished basement in January will need more than ~4,434 BTU/hr. Use our BTU calculator for a precise estimate.
Space Heater Edition Comparison
| Model | Algorithm | Hash Rate | Power | BTU/hr | Best For |
|---|---|---|---|---|---|
| S9 Space Heater | SHA-256 | ~13.5 TH/s | ~800–1,300W | ~2,730–4,434 | Entry-level Bitcoin mining + heat |
| L3+ Space Heater | Scrypt | ~504 MH/s | ~800W | ~2,730 | Entry-level Scrypt mining + heat |
| S19 Space Heater | SHA-256 | ~50–95 TH/s | ~1,500–3,250W | ~5,100–11,090 | Flagship Bitcoin heater, large rooms |
| L7 Pivotal Edition (this unit) | Scrypt | ~3.5 GH/s | ~1,300W | ~4,434 | Premium Scrypt heater, diversification |
All editions feature D-Central’s quiet fan conversion, custom firmware, and 24-hour soak testing. See the full Bitcoin Space Heater lineup or read which miner makes the best space heater.
Frequently Asked Questions
Why Scrypt instead of SHA-256?
Diversification. If you already own a SHA-256 space heater (like the S19 Space Heater Edition), adding an L7 Pivotal gives you hash rate on a completely different algorithm. You mine Litecoin and Dogecoin simultaneously through Scrypt merged mining, and most pools can auto-convert to Bitcoin if you prefer. Having hash rate on multiple algorithms means you are not dependent on a single network’s difficulty and fee dynamics.
Why is the power capped at 1,300W? Can I raise it?
No. The 1,300W cap is a thermal safety boundary. This build runs two hashboards (down from four) with fan capacity and heatsink headroom sized for exactly this power level. Exceeding 1,300W risks insufficient cooling, shortened component life, and thermal fault shutdowns. The Vnish power slider is pre-locked at this limit. This is not a performance restriction — it is the engineering spec that keeps the machine stable and safe indoors.
Can I run this on a standard 120V outlet?
Yes. The Pivotal PSU modification converts the APW12 to accept 110–120V input. At ~1,300W on a 120V / 15A circuit, the continuous draw is approximately 10.8A — within the 12A continuous rating of a 15A breaker (80% rule). One unit per circuit. Do not share the circuit with other high-draw appliances. See our electrical requirements guide for details.
How loud is it?
Substantially quieter than a stock Antminer L7, which runs at 75+ dB. The quiet 120 mm fans and internal air deflector produce a steady low-frequency hum. It is comparable to a forced-air furnace register or a loud fridge — present but not intrusive. The two-hashboard configuration helps: fewer chips generating less heat means the fans do not need to work as hard, which means less noise and fewer sudden ramp-ups.
What Litecoin/Dogecoin pool should I use?
Any Scrypt pool that supports merged mining. F2Pool, LitecoinPool, and ViaBTC are common choices. Most pools mine LTC and DOGE simultaneously (merged mining is built into the Scrypt algorithm). Some pools offer auto-conversion to BTC at withdrawal. Configure your pool and wallet in the Vnish dashboard — it takes about two minutes.
Is this unit new or refurbished?
Refurbished. Every L7 Pivotal Edition starts with a sourced Antminer L7 that we fully disassemble, clean (dust removed from heatsinks and channels), inspect (connectors, harnesses, thermal interface material), convert (Pivotal PSU mod, fan swap, hashboard reconfiguration), flash (Vnish), and soak-test under load for 24 hours. We only ship units that meet hash rate, thermal, and acoustic targets at the 1,300W ceiling.
What is the Pivotal Edition vs. other D-Central editions?
D-Central builds several custom ASIC editions. The Pivotal Edition is defined by the Pivotal PSU modification that enables dual-voltage 110–240V operation — specifically converting power supplies that natively only support 240V. The Slim Edition focuses on compact form factor. The Loki Edition is our 110V-native single-hashboard build. Each edition is a different answer to the question: “How do I run an industrial ASIC in my home?”
What is the Hashboard Airflow Inlet Divider?
A precision-fit internal deflector that guides intake air evenly across both active hashboards. With two boards removed from the four-board chassis, the internal air path changes. Without the divider, one board can run hotter than the other, causing uneven performance and fan speed spikes. The divider is included pre-installed. If you ever need a replacement, we sell it separately: Hashboard Airflow Inlet Divider.
What warranty does this come with?
90-day warranty on D-Central’s conversion and tuning work — that covers the Pivotal PSU mod, fan swap, hashboard reconfiguration, firmware setup, and soak testing. Modifying the base machine may affect the original Bitmain manufacturer warranty. If anything goes wrong within 90 days, we handle it with priority repairs. After warranty, our ASIC repair lab is always available.
Can I add a third or fourth hashboard later?
Not recommended with this build. The Pivotal Edition is engineered around two hashboards at 1,300W. Adding boards would exceed the thermal and power envelope, requiring different fans, a different PSU configuration, and a higher power cap — which would make it louder and unsuitable for residential use. If you want maximum Scrypt hash rate from an L7, that is a different build for a different room (or a dedicated mining space with proper ventilation and electrical).
Why D-Central
The L7 Pivotal Edition exists because we asked a question nobody else was asking: what if you could mine Scrypt and heat your home from the same machine, on a standard outlet? We have been building mining heaters in our Quebec workshop since 2016 — hacking institutional ASICs into home appliances. The Pivotal PSU modification is our design. The Hashboard Airflow Inlet Divider is our design. The tuning profile is ours. This is not a stock L7 with new fans taped on. It is a ground-up residential conversion.
When something breaks, we fix it. Our ASIC repair lab has serviced thousands of miners. When you need help tuning or placing the unit, our support team mines too — we run the same machines we sell.
Every hash counts. Yours should count toward heating your home and diversifying the hash rate across multiple algorithms and networks. Start mining Scrypt. Start heating. Explore the full Space Heater lineup.
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