HELM One in Chalk standing proudly in a sunlit period living room, its signal-orange line running to a porthole panel fitted in the sash window

Numbingly cold air
you don’t have to hide.

Instant relief on the hottest days, from the first machine created from the ground up for people who really care about great design.

Join the waitlist £1,190 · Ships summer 2027

Not just a pretty face.

HELM One looks great — but the aesthetics are the least premium thing about it. At 44 dB(A) it's one of the quietest freestanding machines you can buy. 12,000 BTU means the coldest air on demand. And mechanical switches throughout mean the software can never let you down — because there isn't any.

HELM One in Signal Orange beside open French windows, its orange line sweeping out over the balcony rail

The window part, finally taken seriously.

Every portable air conditioner ships with an apologetic sheet of plastic and a hose it hopes you'll hide. HELM One ships with the Fitting — made to your window — and a line we're actually proud of.

  • The lineSmooth silicone in the colour you choose, one confident curve from the unit to the window. It is never, ever corrugated.
  • The portholeA machined-aluminium port with an oversized knurled rosette and a quarter-turn lock — closer to a camera mount than to plumbing.
  • InThe panel slots into your window and seals with a firm push. Minutes, not a morning. No screws, no drilling, no contractor.
  • OutLift it out and the window is exactly as it was. Nothing for the landlord to ever know about.

Every British window has a Fitting — find yours

Sash

Send 1 — Width
Send 2 — Height

Made to your window and cut to size. It slots in, seals and locks — and leaves no mark when it comes out.

Three parts. One box.

The machine, the line, and a Fitting cut to your window. It arrives together, installs in minutes, and leaves no trace when it goes.

HELM One in Chalk on herringbone parquet, its signal-orange line curving across the floor to a porthole fitted in the sash window
HELM One in Lamp Green with the cream deck, knurled crown, orange pill key and split-flap display reading 23.5

HELM One

Goes in the middle of the room, proudly.
Makes the cold; rolls to wherever summer is.

The Fitting — a made-to-measure cream window panel with the machined aluminium porthole and orange locking ring

The Fitting

Goes in your window, cut to your measurements.
Seals the opening; comes out without a trace.

The Line — coiled signal-orange silicone hose with quarter-turn connectors at both ends

The Line

Runs from the machine to the porthole.
Smooth silicone in your colour, quarter-turn at both ends.

Optional The Bedside Crown — the knurled aluminium crown on its magnetic cream dock

The Bedside Crown

The same crown, within arm's reach at 3am.
Docks magnetically on the deck — so it never asks where it is.

▲ Everything ships in one box, cut to your window ▲ White-glove install available · £49

Every detail earned its place.

We designed HELM One the way you'd design something you have to live with — slowly, stubbornly, and with a deep suspicion of anything that beeps.

  • The crownMachined from a solid billet and knurled so a thumb never slips. Each half-degree lands with a soft, certain click — twenty-eight detents, weighted by hand until they felt inevitable. You will turn it more than you need to.
  • The flapsReal cards on a real spindle, cream on black behind glass. When the room cools, they turn with a soft flutter — the closest thing this machine has to a voice, and the only one it needs.
  • The pillOne orange key. Press for cold, hold for night. That is the entire manual.
  • The darkNo screen, no standby glow, no light watching you sleep. At night it simply disappears, and keeps working.
HELM One — the knurled aluminium crown on the deck
The crown— machined aluminiumTap a detail ↑
October to May

In winter, it becomes the table.

Every other portable air conditioner spends seven months in a cupboard you don't have. HELM One stays out — and earns its floor space.

  • The topCast glass, seated onto the deck in one move. Books, a lamp, a nightcap — and the crown rises through its own cutout, so the machine still takes instruction.
  • The capA machined blanking cap clicks into the porthole where the line lived. The Fitting winters in the window looking intentional, not amputated.
  • The clockThe face becomes a full flip clock. One soft page-turn a minute, silence after dark, and you pull the crown to set it — like a watch.
  • The switch you'll never seeA magnet in the top, a sensor in the deck. Top on, cooling physically can't run. No menu did that.
HELM One in Lamp Green wintered as a side table by a French window, its split-flap face reading 12:35, in a Parisian living room with a green velvet sofa and a green-and-cream checkerboard rug Top-deck close-up of HELM One — the clear Winter Top cap over the knurled aluminium crown and orange pill key, split-flap face reading 12:35
1

Twist

Quarter-turn the line off at both ends. It coils into the channel on the back.

2

Cap

Click the blanking cap into the porthole. Thirty seconds, no tools.

3

Top

Seat the glass top. The flaps turn over to the time, and summer is officially filed.

▲ Winter Top & blanking cap — in the box ▲ Come June, the ceremony runs in reverse

Pick the body. Pick the line.

Four bodies, four lines, sixteen ways to do it. Orange on Chalk is the classic. All-black is the sleeper. Green body, orange line is for the brave.

Body
Line

Chalk body · Signal Orange line — the classic

Four HELM One bodies in a row: Signal Orange, Lamp Green, Chalk and Fell Black, each with the cream deck and split-flap display

What £1,190 buys.

No mystique. Here's the machine with its shirt off — every part that makes it quiet, cold and clean, and why it's there.

A A 700 300 1 SPLIT-FLAP CARTRIDGE NO SOFTWARE TO FAIL 4 WASHABLE FILTER PULL · RINSE · DONE 5 WOOL-LINED CHAMBERS SOUND STAYS INSIDE CONDENSATE → CONDENSER NO TRAY TO EMPTY 2 CROWN + DETENT WHEEL 28 DETENTS, BY HAND 3 FAN + EVAPORATOR 12,000 BTU · TO 35 m² 7 R290 LOOP GWP 3 VS ~2,000 LEGACY 8 DUAL-HOSE PATH NOTHING PULLED BACK IN 6 INVERTER COMPRESSOR ISOLATED · 44 dB(A) HELM ONE — PORTABLE A/C DRG: SERVICE MANUAL SECTION A–A · ELEVATION SCALE NTS · MM

Nothing beeps. Nothing flashes.
Nothing asks where the remote is.

Air conditioning is supposed to relieve stress — then spends all summer adding it. Chirping at every press. Blinking a standby light into your bedroom. Burying the one setting you want three menus deep in an app. HELM One has no screen, no speaker, no menus and no glow. A crown, a key, and flaps that flutter softly when the room changes. Calm isn't a mode. It's the whole machine.

The whole machine, on one card.

Cooling capacity12,000 BTU / 3.5 kW, inverter-driven
CoverageRooms up to 35 m²
Sound44 dB(A) night mode · 52 dB(A) maximum
ArchitectureDual-hose — no negative pressure
RefrigerantR290, GWP 3
ControlsKnurled aluminium crown · orange pill key · nothing else
DisplayMechanical split-flap, cream on black — room temperature at rest, set point while you turn. No screen, no beeps, no standby light
The FittingMade to your window — sash, casement, tilt & turn or Crittall, cut to your measurements · machined porthole with quarter-turn lock · silicone line, 2 m
Winter modeFull flip clock, set by the crown · cast-glass Winter Top + porthole blanking cap included · top-on interlock disables cooling
Body & lineEach in Signal Orange · Lamp Green · Chalk · Fell Black — mix or match, sixteen combinations
Dimensions300 × 300 × 700 mm · 26 kg, recessed castors
Price£1,190 including VAT · £49 white-glove installation optional
First run — 1,500 units

Be first in line.

The first production run ships summer 2027, before the heat does. Waitlist members choose their body and line first, and take £100 off.

Join the waitlist