Ventilation
Positive input ventilation
Honest PIV suitability assessment and installation for appropriate homes with condensation concerns.
Why diagnosis matters
Treat the cause, then repair the damage
Positive input ventilation introduces filtered air to dilute indoor humidity and encourage air movement. It can be useful in suitable properties, but it is not a universal answer to mould.
Technical review
Dan, Director / Surveyor
Last reviewed: July 2026. Advice is general until the property, access and visible evidence have been assessed.
Guarantee & aftercare
Written guarantee terms are matched to qualifying work, with inclusions, exclusions and aftercare explained before acceptance.
What we consider
Possible causes and lookalikes
Whole-home humidity accumulation
Weak background ventilation
Inadequate air transfer
Recurring winter condensation
Inspection method
A clear work sequence
Step 1
Assess suitability
Step 2
Check existing ventilation
Step 3
Specify unit and location
Step 4
Install, commission and explain controls
Scope boundaries
Honest about what the work does—and does not—cover
Electrical work is completed only by appropriately competent personnel. PIV will not repair water ingress, major insulation defects or failed local extract.
Common questions
About positive input ventilation
Is PIV suitable for every home?+
No. Property type, loft conditions, airtightness, extract and the actual moisture source all affect suitability.
Does it replace bathroom extract?+
Usually not. Moisture should still be removed effectively at source in bathrooms and kitchens.
Will it feel draughty?+
A correctly selected and commissioned system should deliver controlled airflow. Settings and diffuser position matter.
Related services
Continue your investigation
Next step
Claim your complimentary survey before choosing a treatment
Tell us what you can see, when it changes and where the property is. Photographs can help us triage the next step.