{"id":22796,"date":"2026-03-24T09:53:37","date_gmt":"2026-03-24T08:53:37","guid":{"rendered":"https:\/\/mag.ebmpapst.com\/en\/?p=22796"},"modified":"2026-03-24T09:53:38","modified_gmt":"2026-03-24T08:53:38","slug":"ice-storage-heat-pump-triton-nullpunkt-a-new-ice-age","status":"publish","type":"post","link":"https:\/\/mag.ebmpapst.com\/en\/industries\/heating\/ice-storage-heat-pump-triton-nullpunkt-a-new-ice-age_22796\/","title":{"rendered":"A new ice age"},"content":{"rendered":"\n

On the work\u00adbench in a Swiss garage lie an engine cooling system, a self-bent composite pipe heat exchanger, the hoses of an antifreeze circuit\u2014and an ebm-papst fan. A water tank stands on the floor. Cable ties, tools and an old brine heat pump complete the makeshift setup. Thomas Degelo, Michael Egli and Pascal Barmet sit around it, tinkering, discussing and forging a plan. \u201cWe asked ourselves why there was no system that provided renew\u00adable heating without going deep into the ground or installing a lot of tech\u00adnology outside. That\u2019s how the idea of imple\u00admenting the prin\u00adciple of an ice storage heat pump on a small scale came about,\u201d says Thomas Degelo.<\/p>\n\n\n\n

From a Garage Start-Up to a Full-Fledged Company<\/h2>\n\n\n\n

Tradi\u00adtional ice storage heat pumps are suit\u00adable for large build\u00adings: hotels, office complexes, or commer\u00adcial build\u00adings. This is because they use large, under\u00adground concrete tanks that hold several thou\u00adsand liters of water. Heat exchangers are located inside these tanks, through which heat from renew\u00adable energy sources is fed into the system. When heat energy is extracted from the storage tank, the temper\u00ada\u00adture drops to 0\u00b0 Celsius; the water freezes, releasing energy that is used for heating. When heat is rein\u00adtro\u00adduced, the ice melts again, and the cycle begins anew. Ice storage heat pumps are designed for seasonal storage manage\u00adment: heat is stored in the summer and retrieved in the winter.<\/p>\n\n\n\n

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The heat transfer fluid flows through the heat exchanger coils and absorbs energy from the ice storage tank. (Images | Nullpunkt AG)<\/p>\n<\/div><\/div>\n\n\n\n

For a single-family home, a typical system like this is too large, too expen\u00adsive, and far too complex. But conven\u00adtional heat pumps also have their limi\u00adta\u00adtions: ground-source heat exchangers require permits, involve exten\u00adsive construc\u00adtion work, and are costly. Outdoor air-to-water heat pumps take up space, require careful noise and site plan\u00adning, and are not to everyone\u2019s aesthetic taste. \u201cAs the three engi\u00adneers and home\u00adowners that we are, we weren\u2019t willing to accept that,\u201d says Degelo. \u201cWe asked ourselves why there wasn\u2019t a system that provides renew\u00adable heating without going deep into the ground or installing a lot of equip\u00adment outside.\u201d That\u2019s how the idea arose to develop an ice storage heating system that could also fit in a garage, a base\u00adment room, or a niche.

In the winter of 2023, the three engi\u00adneers installed the first proto\u00adtype of a compact ice storage heat pump at a colleague\u2019s house. The oil heating system remained connected as a backup, just in case. But the impro\u00advised setup consisting of car radi\u00ada\u00adtors, composite pipes, antifreeze solu\u00adtion and an old fan worked\u2014and was surpris\u00adingly stable at that.

The successful exper\u00adi\u00adment marked the starting point: Devel\u00adop\u00adment of the ice storage heat pump began in 2023, and in 2025 the engi\u00adneers founded nullpunkt AG\u2014with the goal of devel\u00adoping a marketable ice storage heat pump for single-family homes.<\/p>\n\n\n\n

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How does Triton work?<\/h2>\n\n\n\n

Triton consists of three compo\u00adnents: a brine-water heat pump, a compact ice storage tank holding approx\u00adi\u00admately 1,000 liters of water, and an outdoor heat exchanger that trans\u00adfers energy from the ambient air into the storage tank. Instead of storing heat season\u00adally like tradi\u00adtional ice storage systems, Triton oper\u00adates on a daily cycle: At night, the heat pump extracts energy from the storage tank. This causes the water to freeze, and the released heat is used for heating. During the day and in warmer weather, envi\u00adron\u00admental heat is fed back into the storage tank via the outdoor heat exchanger, causing the ice to melt and the cycle to start over. The basis for this lies in what is known as latent heat: When heat energy is extracted from water, it cools down to 0\u00b0 Celsius; after that, heat energy can continue to be extracted without the water getting any colder\u2014it then freezes and remains at 0\u00b0 Celsius. Since the storage tank is regen\u00ader\u00adated entirely via the ambient air, the system requires neither ground-source heat exchangers nor solar thermal energy. This makes Triton easy to install and suit\u00adable for use even in densely built-up resi\u00adden\u00adtial areas.<\/p>\n<\/div><\/div>\n\n\n\n

Winter in summer?<\/h2>\n\n\n\n

But then winter was over\u2014and with it, the real-world condi\u00adtions needed for a true stress test. The three engi\u00adneers didn\u2019t want to wait for the next one. So they simply recre\u00adated it: In a rented under\u00adground parking garage, they set up their own climate lab\u2014complete with a cooling system, humid\u00adi\u00adfi\u00adca\u00adtion, and a control system capable of gener\u00adating frost and fog profiles at the push of a button. \u201cWe were able to bring the chamber down to minus 15 degrees Celsius and 90 percent humidity,\u201d says Degelo. \u201cThis allowed us to specif\u00adi\u00adcally test situ\u00ada\u00adtions that rarely occur together outdoors\u2014and certainly not when you need them.\u201d A year later, Nullpunkt installed the further-devel\u00adoped proto\u00adtype at their colleague\u2019s facility again. It was an excep\u00adtion\u00adally cold winter with plenty of freezing rain\u2014the perfect endurance test. Based on these tests, Nullpunkt made final adjust\u00adments. The start of series produc\u00adtion was now within reach, but one crucial compo\u00adnent was still missing.<\/p>\n\n\n\n

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At night, Triton is barely audible compared to other heat pumps on the market\u2014we owe this largely to this fan.<\/p>\nThomas Degelo, CEO Nullpunkt AG<\/cite><\/blockquote>\n<\/div>\n<\/div>\n\n\n\n

The very first proto\u00adtype ran on an old ebm-papst fan that was orig\u00adi\u00adnally intended for another project by Degelo\u2019s engi\u00adneering firm. Its purpose was to convey the ambient air through the external heat exchanger and thus regen\u00aderate the ice storage tank. \u201cI was already familiar with ebm-papst from my time in building services engi\u00adneering, so I know how effi\u00adcient their prod\u00aducts are,\u201d says Degelo.<\/p>\n\n\n\n

The AxiTone is unbeat\u00adably quiet<\/h2>\n\n\n\n

As devel\u00adop\u00adment progressed and the team needed a new, more effi\u00adcient and signif\u00adi\u00adcantly quieter fan, nullpunkt contacted ebm-papst in Switzer\u00adland. Samuel Schlit\u00adtler, sales repre\u00adsen\u00adta\u00adtive at ebm-papst in Switzer\u00adland, quickly came up with the right sugges\u00adtion: the AxiTone, an axial fan specially devel\u00adoped for heat pumps with partic\u00adu\u00adlarly quiet oper\u00ada\u00adtion.<\/p>\n\n\n\n

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