Air quality in low energy buildings.
Updated: Jan 21
A well written article in the RIBA Journal on air quality in Low energy buildings, by Justin Bere.
By their very nature Passive House buildings are well insulated with high levels of airtightness.
To avoid condensation in such airtight buildings, stale humid air generated by the occupants must be extracted and replaced with fresh external air by way of a heat exchanger (part of a Mechanically Ventilated Heat exchange unit or MVHR).
Low energy buildings should be considered simple machines. All machines are an assembly of components working together. Remove a single component and the machine will fail.
If we are to reduce the carbon footprint of our buildings we need to understand this concept. Removal of the ventilation component of the machine will result in humid internal conditions. Left unchecked the building fabric will suffer interstitial condensation, lose its insulation properties and at worst, the building will decay.