Condensation is often described as an air-conditioning problem, but the cause may involve outdoor air, cooling operation, thermal bridges and leakage through the building envelope. The first step is to establish when and where moisture appears rather than assume every stain has the same cause.
Separate condensation from water ingress
Surface condensation tends to follow cold surfaces and humid conditions. Localised staining beneath a roof, window or plumbing installation may indicate water ingress or an escape of water. Moisture readings, temperature, relative humidity and a record of operating conditions help distinguish these mechanisms, but a single reading rarely settles the diagnosis.
Review the HVAC and fresh-air arrangement
The investigation should identify the cooling units, return-air path, fresh-air provision, extract ventilation and controls serving the affected rooms. Cooling performance, condensate drainage, filters and commissioning information may be relevant. In multi-unit buildings, the apartment cannot always be assessed in isolation from central fresh-air or district cooling systems.
Inspect the building envelope
Window and balcony-door seals, recessed ceilings, insulation continuity and poorly sealed penetrations can admit humid external air or create colder internal surfaces. A survey should map the pattern of damage against these details and recommend targeted testing where access or records are limited.
Questions clients ask
Is mould in an apartment always caused by the AC?
No. HVAC operation is one possible factor. Water ingress, air leakage, thermal bridging and occupant conditions should also be considered.
Will a thermal camera identify the cause?
Thermal imaging can help locate temperature differences under suitable conditions, but it does not by itself prove the source of moisture.
What information helps a humidity investigation?
Floor plans, HVAC drawings, maintenance and commissioning records, photographs showing when damage appears, and access to affected rooms are useful.
Inspection scope and conclusions depend on the property, access and information available. Inspec can advise on an appropriate appointment for the specific building.
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