Stale Air

In UK residential construction and retrofit contexts, stale air describes degraded indoor air quality resulting from insufficient ventilation.

This condition manifests through measurable pollutant accumulation:

• CO₂ Concentration: Frequently exceeds 1,000 parts per million in poorly ventilated homes (contrasting with 400 ppm outdoor levels)
• Chemical Contaminants: Includes volatile organic compounds (VOCs) from materials like medium-density fibreboard and synthetic floor coverings
• Biological Factors: Microbial VOCs from damp issues prevalent in pre-1919 housing stock (35% of UK homes)
• Particulates: Aggravated by traditional heating methods still found in 23% of English properties

Health & Comfort Impacts
Short-term exposure typically causes:

• Perceived stuffiness and odour retention
• Acute symptoms like concentration difficulties

Chronic exposure risks include:

• Worsening asthma (affects 8 million UK residents)
• Sick building syndrome patterns