Checklist: how to prepare a place for an ASIC miner at home (power, noise, ventilation, internet)

Before you plug in an ASIC miner, you need to have five things sorted: a strong enough power supply, noise, heat removal, wired internet and a dry, dust-free place. A large air-cooled machine of around 3.5 kW draws over 15 A at 230 V, hums at around 75 dB and heats like a 3.5 kW electric heater. Small home miners up to 0.8 kW can run from an ordinary socket in a flat.

Summary

• You calculate the current as power draw in W divided by 230 V. A machine above roughly 2.5 kW belongs on a dedicated circuit. Above roughly 2.9 kW a 16 A circuit is no longer enough.
• Do not use extension cords or power strips for a continuous load. Always have the circuit assessed by an electrician.
• A miner with a 3 kW power draw needs to exchange roughly 900 m³ of air per hour if the air is heated by 10 °C.
• A classic ASIC runs at 75–76 dB. Only a quiet home model (35–55 dB) belongs in a flat; a large machine goes in a garage or cellar in a soundproof box.
• The warranty does not cover damage caused by an undersized power supply, moisture, condensation, dust or insufficient cooling.

Checklist: what to have ready before buying and installing an ASIC miner

Go through the 6 groups below before you order. Every point you cannot tick off means extra work or a different machine. You will find detailed procedures in the linked guides.

Power

• ✔ You know the machine's power draw in W and have calculated the current: power / 230 V. For example, Antminer S21 XP 270 TH/s: 3,645 W / 230 V = 15.8 A.
• ✔ You know which circuit breaker the circuit is on (usually 10, 16 or 20 A) and what else runs on it.
• ✔ The continuous load does not exceed roughly 80% of the breaker rating. A miner runs 24 hours a day, not a few minutes like a kettle.
• ✔ A machine above roughly 2.5 kW has a dedicated circuit. Above roughly 2.9 kW (12.8 A, i.e. 80% of 16 A) a 16 A circuit is no longer enough. The breaker, socket and cable cross-section are then designed by an electrician.
• ✔ The power cable can handle the machine's continuous current. According to available manuals, the Antminer S21 has a P14 inlet and comes with a C20–P13 cable for PDUs with C19 sockets. Check this for your model.
• ✔ A water-cooled machine (Hyd) is usually powered at 380–415 V from a three-phase supply, for example the Antminer S21+ Hyd. The supply and PDU are designed by an electrician.
• ✔ There is no extension cord or power strip between the socket and the miner.
• ✔ An electrician has assessed the circuit or installed a new one.
• ✔ You have calculated the running cost: power × 24 h × price per kWh. The method is explained in the article ASIC miner power consumption and J/TH.

Location and noise

• ✔ You know the machine's noise level in dB according to the manufacturer (table below).
• ✔ You only put a quiet home model of up to roughly 55 dB in a living room.
• ✔ A 75 dB machine stands in a garage, cellar or utility room, ideally in a soundproof box.
• ✔ You are aware that two identical machines next to each other are 3 dB louder than one.
• ✔ The machine stands on a firm, level surface, not on a carpet, with free space around the intake and exhaust.
• ✔ The place can fit a box: the PC Praha 40 soundproof box has a footprint of 52 × 40 cm, a height of 120 cm and weighs about 50 kg.
• ✔ You have discussed the noise with your family and neighbours and, if renting, with your landlord.

How to reduce noise and which machines are quiet is covered in the guide How to quieten an ASIC miner at home.

Heat and ventilation

• ✔ You are aware that the entire power draw turns into heat. A 3.5 kW machine is a 3.5 kW heater running non-stop.
• ✔ You have a way out for the warm air (window, wall opening, duct) and an equally large inlet for fresh air.
• ✔ The hot exhaust does not flow back into the intake.
• ✔ The intake air is ideally 20–25 °C. For the Antminer S21, Bitmain allows 0–45 °C and 10–90% humidity without condensation.
• ✔ You know what you will do in summer: vent the heat outside or switch the machine to a more economical mode.
• ✔ In winter you can make use of the heat. We have calculated when it pays off in the article Heating with an ASIC miner.

Network

• ✔ An RJ45 Ethernet cable runs from the router to the miner. Large machines do not have Wi-Fi; the Antminer S21 has a 10/100 Mbit/s port.
• ✔ The router assigns addresses automatically (DHCP).
• ✔ The connection is stable. One miner uses around 1 GB of data a month; what matters is consistent latency.
• ✔ In a garage or holiday cottage you have a backup via a 4G/5G router.
• ✔ You do not expose the miner's interface to the internet and you change the default password straight away.

Details on data, latency and backup are in the article What internet mining needs.

Safety and insurance

• ✔ The electrical installation is in good condition, ideally with an up-to-date inspection.
• ✔ Cables do not run under carpets and are not kinked or pinched by doors.
• ✔ There are no flammable materials near the machine, and the room has a smoke detector and a fire extinguisher suitable for electrical equipment.
• ✔ You have asked your insurer whether your home or property insurance covers equipment in continuous operation and what it requires.
• ✔ You know how mining is taxed. An overview is in the article Mining in the Czech Republic: taxes and laws.

Warranty

• ✔ You photograph the label with the serial number and keep the box in case of a warranty claim.
• ✔ You run the machine according to the manufacturer's specification: voltage, temperature, humidity without condensation and official firmware.
• ✔ You know what the warranty does not cover: overvoltage, undersized sockets and cables, moisture, condensation, dust and operation without sufficient cooling.
• ✔ If the machine has travelled in freezing weather, you let it warm up to room temperature for several hours before switching it on.
• ✔ You know the length of the warranty: new machines from us have a 24-month warranty. New miners bought from us and placed in our hosting have a 7-year warranty without exceptions. The terms are on the Warranty and claims page.

What power supply, noise and heat do the machines in our range have?

The machines in the table draw from 17 W to 5,925 W, i.e. from 0.1 A to 25.8 A at 230 V. We are a retailer and we sell all the machines in the table. Power draw and noise are manufacturer figures from our specifications as of 4 Nov 2026; we calculated the current as power / 230 V.

The current is indicative; the actual value varies with voltage and mode. For the Antminer S21 XP 270 TH/s, Bitmain states a maximum input current of 20 A. An ordinary 16 A circuit is therefore not enough for this machine. An electrician will determine which breaker and cable cross-section to use. Noise figures for air-cooled machines apply at full fan speed. For the Antminer S21+ Hyd 395 TH/s, 50 dB is the noise of the machine itself; the outdoor cooler has its own fans.

At home we assume 4.5 Kč/kWh including distribution (a rough figure, typically the twenty-hour D57d tariff; on the standard D02d tariff around 6.4 Kč/kWh, see How much electricity for mining costs). Running a Canaan Avalon Mini 3 37.5 TH/s then costs roughly 86 Kč a day. For the Antminer S21 XP 270 TH/s it is roughly 394 Kč a day. In our hosting, electricity costs from 1,14 Kč per kWh.

Flat, garage, cellar or outdoors: where should the miner go?

Machines up to roughly 0.8 kW and 55 dB belong in a flat; anything more powerful goes in a non-residential space. Each place has its weak point:

The operating temperature range differs even within one manufacturer. Bitmain states 0–45 °C for the Antminer S21 and −20 to 45 °C for the Antminer S21 XP. Both always mean humidity without condensation, which is why outdoor operation is the riskiest. How to clean and monitor a machine in such an environment is described in the guide ASIC miner maintenance.

How much air does a 3 kW miner need to remove?

Roughly 900 m³ per hour if the air warms up by 10 °C as it passes through the room. This follows from the formula for the sensible heat of air:

q = P × 3,600 / (ρ × c_p × ΔT)

• q = airflow in m³/h
• P = heat output in kW (for a miner it equals the power draw)
• ρ = air density 1.202 kg/m³
• c_p = specific heat capacity of air 1.005 kJ/(kg·K)
• ΔT = how many °C the air warms up by

For 3 kW and ΔT 10 °C: q = 3 × 3,600 / (1.202 × 1.005 × 10) ≈ 894 m³/h. For a quick estimate, q ≈ 3 × power in W / ΔT is enough.

The less you want the room to warm up, the more air you need to exchange. The same amount of fresh air must flow into the room at the same time. Otherwise the warm air returns to the intake and the machine reduces its output or shuts down.

Through a 200 mm duct, 900 m³/h flows at around 8 m/s; through a 160 mm duct at around 12 m/s. A narrower duct and more bends mean higher resistance and more noise. For a longer run, consider an inline duct fan. The overall design for several machines is covered in the article Cooling a mining farm.

What should you watch out for in terms of safety?

A miner draws 0.2–6 kW continuously, so every weak point in the installation shows up as heat. These principles are general and do not replace an electrician:

• Extension cords and power strips are not made for the continuous load of a large machine. A cable wound on a reel heats up even more under load.
• Cables should be original or rated for the machine's continuous current. Push the connector fully home and never reconnect it under voltage.
• A socket that is warm to the touch, discoloured or smells burnt is a signal to switch the machine off and call an electrician.
• A tripping circuit breaker means an overloaded circuit. Never replace the breaker with a stronger one – it protects the wiring in the wall.
• An inspection of an older installation is worth doing before installation, especially with aluminium wiring. The electrician will also check the residual current device and the condition of the sockets.
• Fire risk is reduced by keeping distance from flammable materials, leaving the intake and exhaust uncovered and installing a smoke detector.

Do not make changes to the electrical installation yourself. Consult an electrician who will assess the circuit for the specific machine and your installation. How to connect a miner to the network and set up a pool is described in the guide How to connect an ASIC miner.

When is hosting simpler than preparing a place at home?

If you end up needing a dedicated 20 A circuit, an exchange of over 1,000 m³ of air per hour and a soundproof box, hosting is usually simpler. We take care of installation, connection, monitoring and service, and electricity costs from 1,14 Kč per kWh. New machines bought from us and placed in our hosting have a 7-year warranty. When you buy a machine for hosting, you pay a discounted machine price; hosting is paid separately.

At home, mining mainly makes sense when the heat replaces electric heating or when it runs on surplus solar power. You will find the calculations in the article Does crypto mining at home pay off in the Czech Republic?

What next

• PC Praha soundproof box – our own production. According to the description, the 40 box quietens an Antminer S19 from about 80 dB to roughly 36 dB; the double box is for machines up to 5 kW.
• Quiet miners for home mining – machines for an ordinary socket with noise from 35 dB.
• ASIC miner hosting – locations, electricity prices and monitoring in the data centre if you do not have space at home.

Sources

• Bitmain: Antminer S21 specifications (voltage, max. current 20 A, operating temperature and humidity, network)
• Bitmain: Antminer S21 XP specifications (power 3,645 W, max. current 20 A, noise 76 dBA, −20 to 45 °C)
• Vipera Tech (retailer): Antminer power connectors (P14, C20–P13, C14)
• Canaan: press release on the Avalon Q (power 1,674 W, noise 45–65 dB)
• Hashrate Index: Avalon Mini 3 – modes, power draw and noise
• Engineering ToolBox: Sensible Heat Flow – formula and properties of air