How do I calculate the carbon footprint of an RO water purifier?
List the parts by weight: plastic body, membrane, filters, pump, adapter and tank, with supplier figures. Add the plant's moulding and assembly electricity per unit and packing. Use-phase electricity is a separate figure, stated with its assumptions.
Materials
- ABS or PP body and tank by weight.
- RO membrane, sediment and carbon cartridges.
- Booster pump, solenoid valve, adapter, PCB and UV lamp.
Making
- Moulding of the body, if done in house.
- Assembly, leak and TDS testing.
- Carton, thermocol or moulded pulp inserts.
Per unit
Report cradle to gate per unit. If a buyer wants use phase, state the daily litres, hours and years assumed.
Worked example: purifier assembly per unit (one month)
- Electricity: 30,000 kWh x 0.710 = 21,300 kg CO2
- Units passed: 20,000
- Plant total: 21,300 / 20,000 = 1.065 kg CO2 per unit
- Add plastics, membrane, filters and pump for the full figure
Inputs are illustrative; use your own bills and production records.
What Senseible does here
Senseible reads the plant's electricity bills (CEA grid factor 0.710 kg CO2 per kWh, CO2 Baseline Database version 21.0) and fuel invoices (IPCC 2006 defaults) into a fingerprinted Scope 1 and 2 record, the plant-level input to a per-unit figure. Bought-in materials go to the supplier evidence trail; product reports are self-declared drafts.
Sources: GHG Protocol Product Standard, ISO 14067:2018, Carbon footprint of products (iso.org), IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults), CEA CO2 Baseline Database, version 21.0
Last reviewed 2026-10-20.