Capacity changes with site conditions
Catalogue litres/day figures depend on temperature and humidity. Cold rooms and late-stage drying usually produce less water than the headline number.
Electrical calculator · dehumidifier / litres/day / drying
Dehumidifier Size Calculator
Estimate litres/day capacity from room volume, temperature, humidity and drying target, then check power requirements.
For damp rooms, flood drying, plaster drying, storage and commercial humidity control.
Field notes
Field notes for Dehumidifier litres/day
Practical checks to run before this calculator result turns into a site decision.
Air movement supports drying
A bigger dehumidifier will not solve dead air pockets. Pair sizing with air mover placement and a drying log.
Plan power and condensate together
Check circuit capacity, pumps, hoses and drain routes before adding more machines to a wet area.
FAQ
Dehumidifier litres/day FAQ
Short answers written for UK temporary electrical and HVAC planning work.
What is the Dehumidifier litres/day used for?
Estimate litres/day capacity from room volume, temperature, humidity and drying target, then check power requirements. It is mainly for temporary HVAC, drying, cooling and site-power planning, especially where a quick pre-check is needed before selecting equipment or changing a temporary setup.
Can this replace BS 7671 design, inspection or testing?
No. It is a competent-person planning aid only. Final decisions still need current BS 7671 requirements, manufacturer data, inspection, testing, risk assessment and the actual site conditions.
What should I verify before acting on the result?
Check room volume, temperature, humidity, condensate handling, air movement, available supply capacity and whether wet leads or RCD nuisance trips are likely. If any assumption is uncertain, use the result as a prompt to investigate rather than as permission to energise.
What does an amber or red result usually mean?
It normally means the margin is weak, an assumption is missing, or the load should be split, staged, moved closer to the supply, reduced or reviewed by a competent electrician before use.
Next tools in this workflow
See super flows
Calculator · desiccant / refrigerant
Refrigerant vs desiccant
Choose a dehumidifier type based on temperature, RH, target and site conditions.
Calculator · dew point / condensation
Dew point risk
Calculate dew point and cold-surface condensation risk, then decide whether heat, dehumidification or airflow is the first lever.
Calculator · drying / power plan
Drying room power plan
Combine dehumidifiers, air movers and support heaters into a staged circuit plan for drying jobs.
Calculator · condensate / pump
Condensate pump head
Check whether a dehumidifier or portable AC condensate route is likely to need a pump or a shorter drain path.