How to Choose a Ventilation System for Your Home
Poor ventilation causes mold, condensation, and health issues. Learn how to select the right system for new builds and renovations.
Proper ventilation is essential for a healthy home. Modern airtight construction reduces natural air exchange, making mechanical ventilation increasingly necessary. The right system removes moisture, pollutants, and stale air while maintaining energy efficiency.
Why Ventilation Matters
Poor indoor air quality causes:
- Condensation and mold growth on windows and walls
- Respiratory issues, allergies, and asthma triggers
- Lingering odors from cooking and bathrooms
- Dust mite proliferation in humid environments
- Structural damage from persistent moisture
Types of Ventilation Systems
Natural Ventilation
Relies on trickle vents and manual window opening. Suitable for older, less airtight homes but increasingly inadequate for modern construction.
- Cost: €200-500 (trickle vent installation)
- Running cost: None
- Best for: Older properties, mild climates
MEV (Mechanical Extract Ventilation)
Central fan continuously extracts air from wet rooms (bathroom, kitchen). Fresh air enters through wall vents.
- Cost: €1,000-2,500 installed
- Running cost: €50-100/year
- Best for: Retrofits, budget-conscious projects
dMEV (Decentralized MEV)
Individual extract fans in each wet room, often humidity-controlled.
- Cost: €200-400 per room
- Running cost: €30-60/year per unit
- Best for: Single room upgrades, rental properties
MVHR (Mechanical Ventilation with Heat Recovery)
Balanced system that supplies fresh air and extracts stale air, recovering up to 95% of heat. The gold standard for new builds.
- Cost: €4,000-8,000 installed
- Running cost: €100-200/year
- Best for: New builds, major renovations, airtight homes
Selection Criteria
| Factor | Natural | MEV | dMEV | MVHR |
|---|---|---|---|---|
| Initial cost | Low | Medium | Low-Med | High |
| Running cost | None | Low | Low | Medium |
| Heat recovery | No | No | No | Yes (90-95%) |
| Filtration | No | Basic | Basic | HEPA available |
| Installation ease | Easy | Medium | Easy | Complex |
| Noise | None | Low | Variable | Low |
Essential Qualifications
When hiring a ventilation contractor, verify:
- HVAC certification: Proper training in ventilation systems
- Building regulations knowledge: Part F (UK) or local equivalent
- Design capability: Ventilation rate calculations for your home
- Commissioning experience: Proper testing and balancing
Questions to Ask Installers
| Question | Why It Matters |
|---|---|
| What ventilation rate do you recommend? | Should be calculated, not guessed |
| How will you commission the system? | Testing ensures proper performance |
| What maintenance is required? | Filter changes, cleaning schedule |
| What noise levels can I expect? | Important for bedrooms |
| Is there a warranty? | Typically 2-5 years |
Cost Factors
- House size: Larger homes need more extract points
- System type: MVHR costs 3-4x more than MEV
- Ductwork: Retrofitting ducts adds €1,500-4,000
- Controls: Smart/humidity sensors add €200-500
Red Flags to Avoid
- No ventilation rate calculation provided
- One-size-fits-all recommendations
- No commissioning included in quote
- Unbalanced quotes (missing ductwork or controls)
- No references from similar projects
Find Ventilation Specialists
Find qualified ventilation contractors in your area to get quotes for your project.