Condensation and ventilation issues Apart from leaks, penetrating, rising damp and flooding there are several other issues which can result in mould and other health related issues.
These include poor ventilation and poorly installed cavity wall insulation.
Better ventilation can often improve air quality in terms of carbon dioxide and dew point condensation by balancing indoor and outdoor humidity levels.
Heat Recovery and both Positive and Negative ventilators can assist in the improvement of indoor Air Quality but airborne contamination is unlikely to be reduced.
A mould contaminated property cannot be decontaminated by ventilation alone and will normally require air decontamination.
My analogy is cooking smells, opening the front door or upstairs window wont stop odours travelling through the property.
Typically negative pressure fans pull contamination out of walls and floor cavities while positive pressure ventilators can push contamination to previously un affected areas.
Cavity wall insulation
Some forms of cavity wall insulation are failing and building occupants are seeing building related illness develop. This usually requires the removal of the often damp insulation, decontamination of both the cavity and the property. Mould Busters have developed systems for both operations.