Combining a miner and a heat pump

The heat pump is the more efficient heater, the miner the one with the side income. Together they cover cases that neither handles well alone.

Setup 1: side by side on the buffer tank

Both heat generators feed the same tank. A controller decides which one runs.

The miner covers the base load. It runs continuously as long as mining brings in revenue and the tank takes up heat. You size its power for the heat demand of spring and autumn, not for the coldest day.

The heat pump covers the peaks. On cold days it cuts in. It also runs alone when the mining revenue falls below the electricity costs.

Advantages of this setup:

• The heat pump can be smaller because it does not have to carry the whole heating load.
• If the mining revenue disappears, the house stays warm.
• If the heat pump fails, the miner supplies basic heat.

The rule for this is simple: the cheaper heat generator runs first. Which one that is changes with the electricity price and the mining revenue and can be determined afresh every day.

Setup 2: the miner as heat source

Here the miner does not work for the heating circuit but for the heat pump. Its warm water replaces the ground probe or outdoor air as the source.

This solves two problems at once:

• The heat pump becomes more efficient. The warmer its source, the less electricity it needs for the same heating output. A source at 25 °C instead of winter outdoor air makes a big difference.
• The miner stays cool. Because the heat pump takes the heat off it at a low temperature, its chips run cold and therefore economically. The heat pump produces the high temperature for hot water.

This way even a miner with a low inlet limit can go into a house with high flow temperatures.

What to watch out for with setup 2

Maximum source temperature. Every heat pump has an upper limit for the temperature of its source. It is often well below what a miner gives off, and it is in the datasheet. A mixing valve keeps the source temperature below it.

Two circuits. The miner circuit stays closed and passes its heat to the heat pump's source circuit via a plate heat exchanger.

The outputs must match. The heat pump extracts less from its source than it gives off as heating output. The miner must not supply more heat than it can take, otherwise it needs a second route for the surplus.

Running times. When the heat pump is off, the miner has nowhere to send its heat. A buffer tank on the source side or a dry cooler absorbs that.

Summer

In both setups the following applies: without heating demand the miner needs another heat consumer or is throttled. For hot water alone, a unit with several kilowatts is too large. Plan summer operation before you fix the miner's power.

Which setup when

• Setup 1 for existing systems. It only needs an additional connection on the tank and a controller.
• Setup 2 for a new build or a renovation, when the heat pump is being newly planned anyway and its manufacturer approves the source temperatures.

Who plans it

Any heating engineer can build setup 1. Setup 2 requires coordination with the heat pump's manufacturer, because it operates outside the usual sources. Get their approval before you order.

Sources

• Fraunhofer ISE: seasonal performance factors of heat pumps in existing buildings, 2025
• Bitmain: S21 XP Hyd, specifications with permitted inlet temperature

As of October 2026. This article shows the principles of the setups and does not replace planning by a specialist contractor.