First ask what happens to the organic material
Drying changes moisture content and often reduces weight, but it does not by itself prove biological stability or compost maturity. Some products sold as OWC may also rely heavily on heating and drying. Ask for measured output quality and downstream handling rather than treating names as standardised.
- Verify whether the quoted system uses biological decomposition, thermal drying or a hybrid.
- Ask whether its discharge requires curing, composting, further treatment or licensed disposal.
- Check acceptable inputs and contamination controls.
Comparison: dehydrator versus OWC
Actual energy and operating conditions are model specific; avoid universal kWh/kg claims.
| Buying question | Food-waste dehydrator | OWC / composting system |
|---|---|---|
| Primary mechanism | Moisture removal / drying | Mechanical conditioning plus specified composting or thermal treatment |
| Output at discharge | Drier food residue; maturity not implied | Processed residue; maturity not implied without evidence |
| Energy use | Depends on moisture evaporated and heating efficiency | Depends on heaters, mixing and cycle/duty requirements |
| Space | Check exhaust/condensate and storage | Check loading, discharge, curing and ventilation |
| Input restrictions | Some systems reject bones, oils or packaging | Feed and contamination limits vary by design |
| Evidence to request | Inlet/outlet moisture and disposal route | Process parameters, stability/maturity and curing route |
The hidden output-disposal question
If food waste is reduced in weight but remains unsuitable for soil application, it still needs an authorised and economical final route. If an OWC discharges partially processed matter requiring curing, this needs space, labour and monitoring too. Do not assume 80–90% weight reduction equals 80–90% treatment efficiency.
Ask for independent test protocols if vendors claim instant fertiliser or certified compost.
Which can fit a hotel, society or institutional kitchen?
A dehydrator may suit a particular moisture-reduction/logistics objective; an OWC can suit a site committed to on-site organic processing with a curing workflow. Neither replaces segregation. Compare daily waste variation, liquids, power tariff, water balance, smell control and staff commitment.
- Get a 24-hour operating schedule and measured connected kW versus kWh.
- Confirm steam/vapour extraction, condensate and noise requirements.
- Document odour-control, effluent and any statutory obligations.
Supplier test before final PO
Ask both vendors to demonstrate processing with representative incoming waste, show scale weights and record output quality; include acceptance conditions, exclusions, training, service and actual post-processing requirements. Compare total system cost, not only machine footprint.
When the question becomes model-specific
This guide stays general. For exact figures on a particular machine, these published pages from the COMPOSTO range are the reference.
Want a second opinion on your site?
Send your site type, city and measured daily wet waste. The COMPOSTO technical team replies with the capacity and checks worth doing next.