Computers run hot. Homes need heat.
DH System turns the waste heat of high-performance computing into heating and hot water for the house it sits in — powered by the roof's solar panels, plugged into the boiler that is already there. A working alternative to the heat pump, and a way to make the energy transition pay for itself.
Two energy problems that happen to be the same shape
Switzerland has to get fossil fuels out of its boiler rooms. At the same time, the world is building computing capacity at a pace never seen before — and throwing its heat into the sky.
Heating is still fossil
37 % of buildings are heated with oil and 17 % with gas; among households the fossil share is closer to two thirds. The go-to replacement, the heat pump, costs around CHF 40,000 for a house of this class, needs an outdoor unit, refrigerants and permits, and loses efficiency on the 60–70 °C radiators most older houses have. Subsidies help — but only if the old system is ripped out, and they cannot carry a national transition on their own.
Computing throws its heat away
That is about 1.5 % of the world's electricity, and the IEA expects it to more than double to around 945 TWh by 2030 as AI workloads grow. Almost every one of those kilowatt-hours ends up as low-grade heat that is fanned into the atmosphere — often after spending even more energy on cooling. Meanwhile, houses a few kilometres away burn gas to make exactly that heat.
Put the compute where the heat is wanted, and both problems shrink at once.
A compute module in the boiler room
The DH System is a compact, immersion-cooled compute module that stands next to your existing boiler. The chips inside — today Bitcoin ASICs, next GPUs for AI and HPC — turn electricity into heat with better than 99 % efficiency. Plate heat exchangers move that heat into your radiators and hot-water tank at 60–70 °C. No outdoor unit, no refrigerants, no change to your radiators.
When the sun shines, the module runs on your rooftop solar and every kilowatt-hour spent computing heats the house. When it doesn't, the boiler you already own takes over — a hybrid that cut fossil consumption by 45 % in our pilot house. And because the compute earns money while it heats, DH System pays the homeowner a cashback of about 4 ct/kWh on solar-powered heating hours. You never touch cryptocurrency or hardware: an annual service contract covers monitoring, maintenance and swaps, just like a boiler.
Solar first
The controller runs the module when your panels produce. Heat is made from your own electricity instead of being exported at a few cents a kilowatt-hour.
Boiler-grade heat
Immersion cooling and brazed plate exchangers deliver 60–70 °C supply water — the temperature old radiators were designed for and heat pumps struggle to reach efficiently.
Swap the chips, keep the plumbing
Hydraulics stay for decades; compute is upgraded every few years. The module is designed so the workload can change — from ASICs to GPUs — without touching the house.
| Criterion | Air-source heat pump | DH System |
|---|---|---|
| Outdoor unit | Required — noise, space, planning | None. Everything stays in the boiler room. |
| Refrigerants | Yes, typically high-GWP gases | None — water and a dielectric cooling fluid |
| Existing 60–70 °C radiators | Efficiency (COP) drops sharply at high temperatures | Native — supply up to 60–70 °C with no penalty |
| Building permit | Often required for the outdoor exchanger | Typically not: indoor, liquid-cooled, no external unit |
| Indicative cost, house + solar | ≈ CHF 72,000 after subsidies | ≈ CHF 52,000, without subsidies |
| Running cost on solar hours | You pay for the electricity you don't export | Heat is free and you receive ~4 ct/kWh cashback |
| Upgrade path | Replace the whole unit | Swap the compute module, keep the hydraulics |
| Cost figures are from the Venthône pilot configuration (≈200 m² house, existing gas boiler, 20 kWp-class PV). Heat pump reference ≈ CHF 40,000 for the unit alone. Site-dependent. | ||
One year of energy in the pilot house
The roof makes 27 MWh a year. The house needs 29 MWh of heat. Routing part of the solar production through the compute module — instead of selling it to the grid for cents — replaces 13 MWh of gas and turns a heating bill into a positive cash flow.
Annual energy flows — Venthône pilot house
MWh per year · measured & modelled≈200 m² house with radiators and a gas boiler, 20.5 kWp rooftop PV. Solar: 3 MWh household electricity, 11 MWh exported, 13 MWh through the DH module as heat. The boiler supplies the remaining 16 MWh in winter. Exported electricity ≈ +CHF 2,100/yr, cashback ≈ +CHF 500/yr, remaining gas ≈ −CHF 2,000/yr.
Solar decides when
The controller (Home Assistant) starts the module when PV output is available and throttles each device between 1.7 and 4 kW to follow the sun.
Chips heat a fluid bath
The compute sits in a dielectric fluid. A pump carries the heat to brazed plate exchangers sized for ~18 kW at ΔT ≈ 20 °C; three devices give ≈10 kW thermal.
Into the existing loop
A pressure-free reservoir feeds the boiler circuit and the hot-water tank. Radiators see 60–70 °C, exactly as before. An optional 600–800 L buffer shifts daytime heat into the evening.
Boiler as backup
In deep winter the existing boiler tops up. Over-temperature and flow sensors protect the loop; monitoring is remote, and faults are fixed before you notice them.
Built, plumbed and running in Venthône since 2022
The first DH System heats the founder's own house. It started as a liquid-cooled rig on a boiler bypass, went through three prototype generations, and now runs as a single-phase immersion-cooled module installed by local plumbers and electricians. Everything is logged: per-device power, tank and loop temperatures, solar production, hashrate.
Solar production vs. heat demand, month by month
The sun peaks in summer, heat demand in winter. The DH module soaks up solar in the shoulder months and daytime hours; a buffer tank carries it into the evening, and the boiler covers the rest. Heat demand: 21,975 kWh space heating distributed by season plus 7,325 kWh hot water spread evenly.
Show data table
- 20.5 kWprooftop PV on the pilot house, ≈27 MWh simulated yearly production
- 3 × ASIC≈3.3 kW each, ≈10 kW thermal peak, power-modulated 1.7–4 kW per device
- 11–18 kWbrazed plate heat exchangers, ΔT ≈ 20 °C, insulated loop
- 1 dayto install: standard plumbing and a 6 mm² electrical feed — the complexity of a boiler swap
- V0.1 → V0.3liquid-cooled waterblocks (2023) to single-phase immersion cooling (2024–25)
- 24/7remote monitoring and control on Home Assistant with open-source miner firmware
Any compute that runs hot
The plumbing doesn't care what the chips are computing. What matters is that the workload is dense, interruptible and paid for — so the heat is free to the household.
Bitcoin ASICs
Proven, interruptible and liquid: a mining ASIC converts more than 99 % of its power into heat, can be throttled to follow the sun, and earns revenue by the hour. DH System runs the firmware and the pool and carries the market risk; the homeowner sees only heat and cashback.
GPUs for AI & HPC
Inference servers and HPC nodes make the same heat with a different invoice. The module is designed to take GPU/HPC variants, so local compute — and its heat — can stay in the valley instead of in a distant data centre that pays to get rid of it.
Hosted until paid off
New devices are first hosted where renewable power is cheapest — Canada, the USA, the Nordics — until they have paid for themselves, then shipped and installed in DH Systems. The homeowner gets cost-neutral compute; we get a fleet we can swap and upgrade in the field.
From six graphics cards to a product
Nine years of building, cooling and re-plumbing compute — first for its own sake, then for the house, now for other people's houses.
- 2017–21
GPU era
First rig with six GTX 1080 Ti, then 23 GPUs and the first immersion-cooling experiments.
- 2022
The house
A 290 m² house in Venthône, a shocking gas bill, 21 kW of solar on the roof and the first liquid-cooled boiler support.
- 2023
ASIC switch
S19 miners on custom waterblocks, bench-tested heat dissipation, custom automation — the first working prototype.
- 2024
Prototype V0.3
Immersion cooling, 3D-designed modular case, support from the Innovation Booster Blockchain Nation Switzerland for two extra iterations.
- 2025
Company & fleet
DH System Sàrl founded in Venthône (October 2025). First devices deployed where renewable power is cheapest, earning their way to the boiler room.
- 2026
Pre-production
Pre-production units built around the hosted fleet; modular 19-inch open-frame design; ASICs hosted in Canada and the USA.
- 2027
Compliance
CE compliance, supply-chain lock-in with plumbing, electrical and immersion-cooling partners.
- 2028
Scale
Pilots of 10–50 systems in Valais, then Switzerland, the EU and North America.
An energy transition that pays for itself
A transition that only works with subsidies stops when the subsidies do. DH System's economics come from the compute: lower capital cost than a heat pump, cashback instead of a bill, and hardware that earns before it heats.
of gas burnt for Swiss home heating
Roughly 5 TWh of gas heat a year and more than 0.4 Mt of CO₂. Valais alone has about 30,000 houses heated entirely with fossil fuel — our first market, and where the first 200 systems will go.
Subsidy-light by design
The pilot configuration costs less than a heat pump plus solar even without subsidies. The compute pays the homeowner back, hour by hour, for as long as the module runs.
Circular and local
No refrigerants, hardware kept out of the e-waste stream, and the value of compute — and its heat — kept in the region. Plumbers, electricians and PV installers in Valais do the installation.
Built in the open
The control stack is Home Assistant and open-source miner firmware, and the prototypes were developed with external knowledge we would not have had on our own: the Innovation Booster Blockchain Nation Switzerland (Innosuisse) funded two additional prototype iterations and the alignment with regulatory standards, and local trades tested that installation really is as simple as a boiler swap. A research partnership on heat-recovery optimisation, seasonal storage and life-cycle assessment is the next step.
Local trades, global hardware
To be sustainable we think locally and globally: cutting-edge hardware from international suppliers, installed and serviced by companies in Valais.
- PlumbingSaniduoInstalled the immersion system — confirmed a straightforward, fast and affordable installation.
- ElectricalDMI Électricité SAA universal, cost-effective electrical installation for the module.
- Hardware & coolingBTC ZoneASIC broker and custom waterblock manufacturing.
- Immersion technologyDCX · Fog HashingCustom immersion-cooling tanks for 2–4 devices.
- Firmware & poolBraiinsOpen-source firmware, power modulation and pool operation.
- Supply & hostingHashlabs · Compass · Zeus Mining · ASIC Hosting CanadaDevice supply and low-cost renewable hosting until payback.
MSc in life sciences; senior scientist and QC project lead in the biopharma industry in Visp. Nine years of building and cooling compute — from six GPUs in 2017 to immersion-cooled ASIC fleets in Switzerland and North America.
He bought a house in 2022, got the gas bill, and built the first DH System in his own boiler room rather than pay CHF 40,000 for a heat pump that didn't fit the radiators.
Talk to us
The first commercial installations are planned in Valais. Whether you have a boiler room, a van full of tools, or racks of compute that run hot, we would like to hear from you.
Homeowners in Valais
A gas or oil boiler, radiators, and a roof for solar — or panels already? Join the list for the first pilot installations and get a free site survey.
Join the pilot listInstallers & PV companies
Plumbers, electricians, boiler service and PV companies: DH Systems are installed and serviced by local trades. Let's talk about a partnership.
Propose a partnershipCompute, research & funding
Operators with heat to place, research groups working on heat recovery or seasonal storage, and funders of the energy transition.
Start a conversation
Data Center @ Home · HPC heat recovery for residential heating
Route des Planettes 39 · 3973 Venthône · Valais · Switzerland
DataCenterAtHomeSystem@gmail.com
CHE-195.272.514 · Registered in the Commercial Register of Valais central