Ventilation Problem Investigation
Independent indoor air quality investigators
When staff or tenants complain that the air is stuffy, stale or dusty, the ventilation is often the cause. We investigate using measured evidence — CO₂, indoor air quality and ventilation hygiene — to establish what is wrong, where, and what should happen next.
Established 1999 · 2,500+ assessments · SafeContractor approved · BOHS Affiliate Member · London & South East
Common symptoms
- Elevated CO₂ levels indicating insufficient fresh air
- Stuffy or stale-feeling air in occupied spaces
- Temperature or humidity control problems
- Persistent odours that don't dissipate
- Uneven air distribution — hot/cold spots
- Increased dust deposits from poor filtration
How we investigate
Understand the complaint
We record where and when problems occur and who is affected.
Measure
We log CO₂, temperature, humidity and, where relevant, particulates and VOCs in affected and comparison areas.
Inspect
We inspect accessible ventilation components for hygiene problems such as dirty filters, fouled coils or contaminated ductwork.
Review operation
We review ventilation run times, BMS settings and occupancy, where information is available.
Report
We explain the likely cause and give prioritised actions, including what to ask your HVAC contractor to check.
What happens next
Most investigations end with a short list of actions: operational changes such as schedules or settings, maintenance such as filter changes or cleaning, or a referral to your HVAC contractor to check specific plant. We can re-test after changes to confirm the improvement.
Limitations and what this assessment cannot tell you
- It does not measure airflow or test mechanical performance
- Findings reflect conditions during the investigation
- Diagnosis of plant faults is for your HVAC contractor, guided by our evidence
What your report includes
- Summary of complaints and affected areas
- Measured results with graphs
- Inspection findings and photographs
- Likely causes
- Prioritised actions and contractor referral points
- Re-test recommendation
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Frequently Asked Questions
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