| Architecture | Capture Mechanism | Failure Mode at Scale | Ozone Risk | Maintenance |
|---|---|---|---|---|
| HEPA Filtration Pleated fibrous media |
Mechanical interception | Saturation in 2–4 months at AQI 300+ | None | Replacement consumable |
| Negative-Ion Generators Charged-particle release |
Electrostatic agglomeration | No collection — particles redeposit on surfaces | Often exceeds UL 867 | Surface cleaning required |
| Industrial ESP Wet-wash, large-format |
Two-stage electrostatic capture | Not engineered for residential acoustic / footprint | Variable, uncontrolled | Sludge handling, plumbing |
| Two-Stage Dry ESP V10 architecture |
Polarised charge + drift collection | Linear loading, no saturation regime | Sub-UL 867 by design | Tap-water rinse, every 2–4 weeks |
SS304 40-mesh on all four intake faces — captures hair, lint, pollen, fibres
Tungsten-wire positive corona — unipolar charge transfer to PM₂.₅
Parallel-plate aluminium array, alternating polarity — electrostatic drift deposition
Activated carbon honeycomb — gas-phase contaminant adsorption
MnO₂ honeycomb — passive O₃ → O₂ decomposition
Backward-curved DC turbine — high static pressure, low acoustic signature
Operating field strength 8.0 kV/cm — set safely below the 10.5 kV/cm arc-inception threshold for 5 mm air gaps per Paschen's law at STP. Margin: 23.8%.
Positive corona generates ~10× lower ozone flux than negative corona at equivalent ion current — chosen specifically to minimise primary O₃ generation at the source.
Inter-plate velocity 1.80 m/s, residence time ~120 ms — sufficient for charged particles to drift across the 2.5 mm half-gap before exiting the collection stage.
Net ozone emission target: < 0.050 ppm (UL 867 limit) — achieved via dual mitigation: minimal generation upstream + catalytic destruction downstream.
Eight tungsten emitter wires, micro-spring tensioned, generate a stable positive corona discharge. Sub-micron particulates are charged via unipolar ion attachment with order-of-magnitude lower ozone byproduct than the negative-corona alternative used in most consumer ionic devices.
Forty-two parallel aluminium plates in alternating-polarity geometry, optimised for the residential particulate size distribution (mass-median ~0.3 µm). Plates are bonded into two interlocking rigid combs — the entire collection surface lifts out as one assembly for tap-water rinsing.
Activated-carbon honeycomb traps gas-phase VOCs and odour molecules. Trace ozone generated upstream then catalytically oxidises adsorbed organics on the carbon surface — regenerating the bed in situ. A downstream MnO₂ layer destroys residual O₃ before exhaust.
Pulling the collector drawer open by 2 mm cuts the EN pin on the +4 kV supply before the metal contacts physically separate. Result: no arcing, no exposed live surface.
The +10 kV ionizer supply is hardware-limited to 1.5 mA. A short-circuit, wet plate, or insect bridging the gap simply collapses the voltage — current can never reach harmful levels.
The MCU continuously monitors HV ground-return current. A leakage above 2 mA — meaning wet plates or unintended path — immediately shuts down both HV rails and flashes the fault LED.
A 100 MΩ resistor permanently shunts the +4 kV bus to ground. After power-off, stored capacitive charge bleeds to <50 V within ~1 second — independent of MCU, firmware, or interlock state.
MnO₂ honeycomb downstream of the corona stage decomposes O₃ to O₂ on contact. No power, no consumables, no maintenance — it operates from the moment the device is assembled.
The PETG shell is intrinsically non-conductive. All HV feedthroughs are silicone-insulated to >15 kV. Cabinet ground is bonded to mains earth — no path from electronics to user-touchable surfaces.