The Spruce Stove isn't stoked with split cordwood or puny sawdust pellets, but rather entire tree trunks are fed into its fiery maw. Photo: Spruce Stove The length of the log dictates the amount of heat produced while simultaneously acting a visual indicator for the amount of heat remaining, a sort of pinewood progress bar. Photo: Spruce Stove The Spruce Stove breaks with tradition by trading out the boring hinged door for a portal that irises open like an airlock on a sci-fi space ship or the opening credits of a Bond flick. Photo: Spruce Stove Many incorrectly assume that flames will leap forth when the iris opens, but the draft pulls the fire in and the front face is cool to the touch less than an hour after the fire is extinguished. Photo: Spruce Stove Hoisting the log into position takes some effort, but a custom designed cart makes pushing another linear foot into the fire as easily as turning the knob of a thermostat. Photo: Spruce Stove "When you have the ability to create almost anything you can think of, it makes you think of what you want," says designer Michiel Martens. "No ordinary stove would do—we wanted a special one that would fit our way of shaping reality." Photo: Spruce Stove "It's a stove for people who are not afraid of a little adventure," says designer Martens. "We made this stove for the adventurers and their living rooms." Photo: Spruce Stove "It's a pity you can't see, feel, and hear it burn," says designer Roel de Boer. "When people use it, they fall in love."Photo: Spruce Stove "I don't like 'safe' designs, for me it needs to have a rough side, a twist, that makes a product or what ever exiting and worth remembering," says Martens.Photo: Spruce Stove

Americans purchased nearly a quarter-million wood stoves last year, and despite their popularity in the modern era the aesthetic options would be surprisingly familiar to colonial-era shoppers. Fortunately for fans of clean lines, Dutch designers Michiel Martens and Roel de Boer have remade the wood-fired heating stove for the contemporary home. Called the Spruce Stove, their bespoke 55-gallon fireplace breaks with tradition by trading out a boring hinged door for a portal that irises open like an airlock on a sci-fi space ship, or the opening credits of a Bond flick.

The stainless steel sheath of the stove will appeal to urban design aficionados, but the unconventional feedstock will excite wannabe mountain men. The machine isn't stoked with split cordwood or puny sawdust pellets—entire tree trunks are fed into its fiery maw. The length of the log dictates the amount of heat produced while simultaneously acting a visual indicator, a sort of pinewood progress bar.

>Martens is adamant that the stove is not dangerous.

Hoisting the log into position takes some effort, but a custom designed cart digs into the timber with a sawtooth grip and allows the operator to push another linear foot into the fire as easily as turning the knob of a thermostat.

The irising movement of the stove's diaphragm is as elegant as a wood stove can be and allows it to handle any diameter log the owner can lug. This development required a significant amount of experimentation by the designers—extreme temperature fluctuations wreaked havoc on early prototypes and required Martens and de Boer to construct several prototypes to work out the kinks.

Martens admits that the Spruce Stove requires more attention than a simpler alternative, still he is adamant that it's not dangerous. Many incorrectly assume that flames will leap forth when the iris opens, yet in practice the draft pulls the fire in and the front face is cool to the touch less than an hour after the fire is extinguished.

The laws of thermodynamics dictate a lot of the design details. The interior of the sheet metal cylinder is lined with fireproof concrete bricks which can withstand the heat of the flames and emit the stored energy as radiant warmth. The stove is fired for a few hours, or about four feet of hard maple, and keeps the space warm throughout the day.

The concept for the stove came about when the designers were moving into a new studio space. They needed a heating source to stay productive during the cool and damp Dutch winter, yet didn't want to sap the creative energy of their shop with a soulless stove. Unimpressed with the commercially available options, they decided to build their own. "When you have the ability to create almost anything you can think of, it makes you think of what you want," says Martens. "No ordinary stove would do—we wanted a special one that would fit our way of shaping reality."

Their way of shaping reality tends towards the odd. Martens previously designed a toilet that has a bladder of its own and de Boer have developed roof tiles that double as miniature gardens so the idea of unconventional home goods was nothing new. "I don't like 'safe' designs, for me it needs to have a rough side, a twist, that makes a product or what ever exiting and worth remembering," says Martens. "I always look for boundaries of expectation, you think you see what it is but there is always a strange angle in material use, shaping, flexibility or just the whole concept.

Despite its adventurous appearance and solid BTU output, de Boer believes it's the stove's acoustics that make it an ideal companion in a workshop. "It's a pity you can't see, feel, and hear it burn," he says. "When people use it, they fall in love."