Positive Input Ventilation for a Flat

Hi Nick I currently install 2/3 PIV units a month and about the same extraction units For a company call trustguard damp proofing and from what I can gather Moisture in the bathroom and kitchen can be removed easily with a trickle and boost NUaire genie extractor fan,a fan that runs constantly at low speed (very quiet) then can either be boosted by a switch or automatically on humidistat setting (detects moisture levels)so drawing out moisture 24/7. Moisture from either of these rooms travels so can cause problems throughout out the flat. A PIV unit is for more severe problems and constantly pumps fresh clean air into the property with an added thermostatically controlled heater so the unit is not pumping cold air into the property. From what I can gather (don't quote me on this) Mould can't grow on clean fresh air been pumped into the property. But I'm just an electrician who fits them for this company to be honest They are the experts