The Home

Water boils at 89.99 °C. Two routes (Antoine, Clausius-Clapeyron) agree to 0.2 K. Starch, egg white and pasteurisation are fine; kidney-bean lectin and soybean trypsin inhibitor need 100 °C, and a quarter of the staple diet is soybean, so the pressure cooker is a mandatory part of the food system (+100 kPa gauge → 115 °C). Oven convection is 0.60× natural, 0.69× forced - the fan is not optional. A 1 kW methane burner would emit 4.7 people's CO₂ and draw 8.2 people's O₂ into a loop with no chimney, on top of the fire ledger's 1.63× spread; induction puts 84% into the pot and pays none of it.

With Earth-sized condenser area the condensing temperature climbs from 40 to 52 °C in the thin argon-rich air and COP falls 17%; the fix is 1.67× condenser area or a fan. Every watt ends up as cabin heat. Whether that heat is a debit or a credit depends on the cavern's heat balance, which no card holds - under declared assumptions the undercity loses 37-58 kW against 19 kW of gains for its first decade. The counter-case, cold piped in from outside for the village, holds both fridge and freezer (surface day maximum −37.5 °C) at the cost of hull penetrations and a punctured vapour barrier; the undercity has no outside. Both printed, neither chosen.

115 people wash 92 kg of clothes per sol in 782 L, plus 172 L of dishes: 955 L/sol against a recycle intake of 659 that never had a line for either. At the plant's own 98.2% closure the net loss is 17 L/sol, lifting city make-up water from 30.3 to 47.5 L/sol. Drying releases 46 kg of water a sol into the air loop (+17% on the condensate line); a heat pump does it for 32 kWh. The 'free' vacuum dryer outside is rejected: venting at 0.6 kPa throws away 1.5× the city's net make-up every sol, and a sealed chamber with a cold trap recovers 99.8% but sublimation costs a quarter more heat than evaporation.

The toilet's flush is not designed but back-calculated from the recycle card's 59 kg/sol flush line: 86 mL per event, one fifty-sixth of an Earth toilet - a vacuum, urine-diverting commode. Pre-treatment acid is dosed at the bowl (the VCD's hard constraint); the dose has no card and is marked not closable. Hygiene water after drinking and flushing is 0.99 L per person-day, so the shower is a 10 L recirculating loop with a 1 L top-up. Shower, dryer and cooking together add 92 kg/sol of moisture, +34% on the condensate line.

Martian dust's 1.5 µm median sits above HEPA's most-penetrating size, so H13 is enough and grade is not the constraint; electrostatic adhesion and 0.5 wt% perchlorate are. Loaded cartridges go to the green (filter-media) stream and the berm, never the purple textile stream that ends in compost and greenhouse soil. How much dust the airlocks bring in per cycle has no card - a 100× scan is printed and three measurements are dispatched to the door-holders.

400 V is 3.3× the safety-extra-low-voltage DC limit, so the home has two tiers: 48 V sockets for anything under 1.5 kW, 400 V hard-wiring for hob, oven, washer, dryer and water heater. At 48 V a 3 kW hob is 62.5 A and needs 34 mm² of aluminium for 2% loss, 69× the conductor mass of 400 V. DC has no zero crossing: a 48 V plug pulled under load draws a 14 mm arc, 400 V 155 mm - sockets handshake before they energise. The mixed-gas breakdown curve (Townsend, mole-weighted, a declared approximation) puts 1 mm at 2.3 kV, 38% below air at the same pressure; the grid's CO₂ coefficients were used only as a known-answer gate.

A 25.9 m³ hard-walled cabin reverberates for 1.6 s; 18 m² of panels bring it to 0.3 s. The WHO night limit is 30 dB(A) and a 42 dB fridge still makes 36 dB in the softened cabin, so not one of eleven appliances may live in a cabin; the commons-to-cabin partition needs 42-49 dB. A fan moving the same mass flow in 0.79× density is 3.2 dB louder. And the cited '+20% sound speed' is −4.3%.

Asked by the polymer line: 278 kg of plastic parts, none above 80 °C continuous, 54 kg in the 60-80 °C margin that wants polypropylene, 37.5 kg both exposed and next to electrics (the microwave shell becomes thin cast iron, the vacuum shell takes a flame-retardant grade). At commons duty a dishwasher's 2500 cycles last 0.95 Mars years, a washer 1.71 - not a household's ten years. Steady plastic replacement is 0.07-0.16 kg/sol, 0.1-0.3% of the polymer line's nameplate: a result that can only exclude. Appliances cannot carry that line's steady state; whether it is built is someone else's demand to show.

Thirteen items decomposed part by part. Shells, insulation, cast-stone tops, printed liners and CO₂ refrigerant are local; compressors, windings, bearings, seals, electronics, heating elements, magnetrons and stainless drums are imported - the foundry's own '0% local' line. Ninety-one units city-wide: 5.66 t, 1.06 t imported; only the imports cross the depot, 1.3-1.8% of one resupply window, once. No 'local manufacturing rate' is given: by mass it flatters, by function it does not.