Understanding Ventilation Systems: Types, Benefits, and Costs

Whether you’re a homeowner, a property developer, or a contractor, understanding the different types of ventilation systems is essential for delivering high-quality, energy-efficient, and healthy indoor environments.

This complete glossary of ventilation types and components will help you choose the right solution—whether you’re building new, renovating, or upgrading ventilation in existing buildings.

Why Ventilation Matters for Every Building

Good ventilation isn’t just about comfort—it’s about health, efficiency, and value. Whether you’re managing a household or running a business, poor indoor air quality can lead to moisture problems, energy loss, and even health complaints. The right ventilation setup ensures:

  • Better indoor air quality
  • Controlled humidity levels
  • Reduced mould and damp
  • Improved energy performance
  • Compliance with building regulations

Types of Ventilation Systems (for Homes and Commercial Projects)

1. Natural Ventilation

A basic and traditional solution. It uses windows, trickle vents, and air bricks to allow air movement.
✅ Pros: Zero operating cost, no electrical parts
❌ Cons: Unreliable in airtight buildings, no control over airflow
✅ Good for: Older buildings or properties with limited budgets

2. Intermittent Extract Ventilation

Uses extract fans triggered by switches or humidity sensors—common in bathrooms and kitchens.
✅ Pros: Simple and cost-effective for moisture control
❌ Cons: No constant fresh air supply to living or working spaces
✅ Good for: Small-scale upgrades or localised moisture issues

3. cMEV (Centralised Mechanical Extract Ventilation)

A continuous extraction system that removes stale air from “wet” rooms via a central fan. Fresh air enters through background vents.
✅ Pros: Low-maintenance, no need for user interaction
❌ Cons: No heat recovery
✅ Good for: Mid-range residential builds or apartments

4. MVHR (Mechanical Ventilation with Heat Recovery)

The top-tier ventilation system for energy efficiency and air quality. MVHR extracts stale air and supplies filtered, fresh air—recovering up to 90% of the heat.
✅ Pros: Energy savings, balanced air, excellent comfort
✅ Good for: Passive houses, NZEB homes, office buildings, luxury renovations
❌ Cons: Requires upfront investment and duct planning

5. DCV (Demand-Controlled Ventilation)

DCV systems adjust airflow based on demand — typically using sensors to detect CO₂ or humidity. They are mostly extract-only systems and do not include heat recovery. DCV is more common in retrofits and multi-family buildings due to its simpler setup.

✅ Key Benefits of DCV:

  • Lower installation cost
  • Requires less ducting
  • Simple to retrofit
  • Energy efficient (ventilates only when needed)

❌ Potential Drawbacks:

  • No heat recovery = higher heating bills
  • No fresh air supply to living areas
  • Less effective in airtight homes
  • No filtering of incoming air

6. dMVHR (Decentralised Mechanical Ventilation with Heat Recovery)

These are standalone units installed room-by-room, often through the external wall, with built-in fans and a heat exchanger.
✅ Pros: Quick to install, no ductwork required
✅ Good for: Single-room applications, retrofits, or where full MVHR ducting is impractical
❌ Not suitable as a whole-house solution for most homes
❌ Often fails to meet Part F ventilation flow rates in new builds

💡 Note for installers and developers: While dMVHR can be helpful in some retrofit or commercial scenarios (e.g. student housing, hotel rooms), it covers only the local room—not the entire property. Over 90% of homes in the UK and Ireland use centralised MVHR for compliance and performance.

7. PIV Ventilation

Positive Input Ventilation system (PIV) is a whole-house ventilation method that continuously introduces fresh, filtered air into a home to improve indoor air quality and reduce moisture. Typically installed in the loft, a PIV unit draws in filtered outdoor air and gently pushes it into the property, creating a slight positive pressure. This constant airflow helps drive out stale, humid air through natural leakage points such as vents and window gaps. In Ireland’s damp climate, this process is particularly effective at preventing condensation, dampness, and mould in existing homes.

Advantages of PIV systems:

  • Effectively reduces condensation and mould growth, protecting walls and furnishings.

  • Improves indoor air quality by filtering pollutants such as dust, pollen, and exhaust fumes.

  • Supports respiratory health for occupants with allergies or asthma.

  • Quiet, low-energy operation with minimal maintenance—usually just filter replacement.

  • Modern PIV units can include heat retention or variable-speed controls to enhance comfort and efficiency.

Limitations of PIV systems:

  • May cause minor heat loss in winter if the loft is poorly insulated or lacks a heater module.

  • Upfront cost is higher than simple extractor fans.

  • Performance depends on airtightness—too many leakage paths can reduce effectiveness.

  • Unlike MVHR (Mechanical Ventilation with Heat Recovery), PIV systems do not recover heat, making them less suited to new nZEB-standard or airtight homes.

Key Mechanical Ventilation Components (Know What You're Installing)

Air Valves (Supply & Extract)

  • Supply valves deliver filtered air to bedrooms, living rooms, offices
  • Extract valves remove stale air from kitchens, WCs, and utility rooms
    Proper positioning and balancing are essential for efficient airflow and compliance.

Filters
Ventilation filters improve air quality and protect the system.

  • G-grade filters: Basic dust and particle protection
  • F-grade filters: Enhanced filtration for allergens, pollen, and fine dust
    ✅ Tip for business owners: Promote filter changes as part of routine servicing

Ductwork
The unseen backbone of any mechanical system. Ducts connect valves to the central unit.

  • Choose rigid or semi-rigid ducting based on space and budget
  • Proper installation prevents leaks and noise
    ✅ Good ductwork = better system performance and happier clients

Heat Exchanger
At the heart of every MVHR unit, the heat exchanger transfers warmth from outgoing air to incoming air without mixing them.
✅ Up to 90% heat recovery = lower heating costs
✅ Great selling point for energy-conscious clients

Control Panel / User Interface
Modern ventilation units include smart controls that allow users to:

  • Set airflow rates
  • Monitor filter status
  • Activate boost mode or summer bypass
  • Integrate with smart home systems or use app-based control
    ✅ Ideal for developers: Smart features are a strong selling point in new builds

Boost Mode
Temporarily increases airflow during high-use times (cooking, showering, gatherings). Can be triggered manually or with sensors.
✅ Improves comfort and reduces humidity spikes fast

Summer Bypass
Helps cool the home on warm nights by bypassing the heat exchanger.
✅ Reduces indoor overheating in summer months
✅ Increases occupant satisfaction without extra energy use

Final Thoughts for Business Owners and Installers

Whether you’re fitting out a new home, upgrading a commercial unit, or advising a client, ventilation is no longer optional—it’s a crucial part of every energy-efficient, comfortable, and healthy building.

Investing in the right ventilation system adds value to your work, improves customer satisfaction, and ensures compliance with modern building standards. MVHR and dMVHR systems are especially worth offering to eco-conscious clients or anyone focused on long-term energy performance.

👉 If you need professional advice, installation, or custom solutions for your project, check out our ventilation services and see how we can help.

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