🏠 How to Install an MVHR Ventilation System (Complete 2025 Guide)

Published by: Ventilation Superstore
Updated: October 2025

What Is an MVHR System?

MVHR stands for Mechanical Ventilation with Heat Recovery.
It’s a modern, energy-efficient system that extracts stale air from inside your building and supplies filtered, fresh air — while recovering up to 96% of the heat from the outgoing air.

That means better air quality, less condensation, and lower heating costs — all from one smart system.

How MVHR Systems Work

Here’s how it functions step-by-step:

Extract Air: The system removes stale, moist air from kitchens, bathrooms, and utility rooms.

Recover Heat: The extracted air passes through a heat exchanger, transferring warmth to the incoming air.

Supply Fresh Air: The warmed, filtered air is supplied to living spaces and bedrooms.

Constant Circulation: Fans run continuously, maintaining balanced airflow and indoor comfort.

This process keeps your home dry, fresh, and energy-efficient all year round.

Can You Install MVHR Yourself?

Installing an MVHR system can be a DIY project for experienced renovators, but it usually requires professional input for design, ducting, and commissioning.

💡 Tip: We always recommend having your system designed or checked by a ventilation specialist — especially for new builds or energy-efficient homes.

That said, here’s what’s typically involved.

Step-by-Step Guide: Installing an MVHR System

Step 1: Planning and Design

- Measure your home’s size and layout.

- Calculate airflow rates for each room (based on building regulations, e.g., UK Part F).

- Choose the correct MVHR unit size and model for your property.

- Plan duct routes for extract and supply air — keeping them as short and straight as possible.

💡 Pro Tip: Use rigid ducting where possible — it’s quieter and more efficient than flexible ducting.

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Step 2: Choosing Locations

- Install the MVHR unit in a loft, utility room, or plant cupboard.

- Ensure easy access for maintenance (filter changes).

- Keep the unit within the building’s thermal envelope to reduce heat loss.

- Locate intake and exhaust terminals on an external wall or roof, spaced well apart.

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Step 3: Installing the Ductwork

- Connect the supply ducts to living spaces (bedrooms, lounge, office).

- Connect the extract ducts to wet rooms (kitchen, bathroom, WC).

- Use acoustic ducting or silencers to reduce noise.

- Seal all joints securely with airtight duct tape and gaskets.

💡 Tip: Label your ducts during installation — this makes commissioning much easier later.

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Step 3.5: Mounting Tips — Installing Your MVHR Unit Safely and Efficiently

Proper mounting is key to ensuring your MVHR system runs quietly, efficiently, and lasts for years. A poorly mounted unit can create unwanted vibration noise or stress the duct connections. Here are our best tips:

✅ Choose a Solid Mounting Surface

- Always fix your MVHR unit to a sturdy wall, ceiling joist, or floor platform.

- Avoid plasterboard or thin partitions — vibration can travel through these materials.

- If mounting in a loft, use a plywood baseboard fixed across joists for stability.

✅ Minimise Noise and Vibration

- Use anti-vibration mounts, rubber pads, or wall brackets with damping feet.

- Maintain a small gap between the unit and the wall to absorb movement.

- Add acoustic ducting on both supply and extract sides to reduce fan hum.

✅ Plan for Condensation Drainage

- Mount the unit level or slightly tilted toward the drain point.

- Connect a condensate hose securely and direct it to a waste outlet or soakaway.

- Use a trap in the condensate line to prevent odour backflow.

✅ Ensure Service Access

- Leave at least 300mm clearance around filters, controls, and duct connections.

- Make sure it’s easy to remove panels for cleaning and servicing.

- If the unit is in a loft or cupboard, consider adding a light and walkway boards for safe maintenance.

✅ Keep It Inside the Thermal Envelope

- Try to keep your MVHR unit within the insulated area of the home — not in an unheated loft if possible.

- This improves efficiency and prevents heat loss through the ducting.

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Step 4: Connecting the MVHR Unit

- Mount the unit on a vibration-dampening bracket or platform.

- Connect ducts to the unit’s labelled spigots (supply, extract, intake, exhaust).

- Install condensate drain to prevent moisture buildup.

- Ensure electrical connection is performed safely — ideally by a qualified electrician.

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Step 5: Balancing and Commissioning

Once installed:

- Check for air leaks and proper sealing.

- Balance airflow rates using dampers or adjustable vents.

- Test fan operation, filters, and sensors.

- Record system settings for future maintenance.

💡Important: A properly balanced system ensures each room gets the correct airflow — critical for efficiency and comfort.

Ongoing Maintenance

To keep your MVHR system running at peak performance:

- Clean or replace filters every 3–6 months.

- Wipe down air valves and vents.

- Check ductwork for blockages or dust buildup.

- Book a professional service every 1–2 years.

Regular maintenance keeps your air clean, your home healthy, and your energy bills low.

Benefits of Installing an MVHR System

✅ Fresh, filtered air all year round
✅ Reduced condensation and mould
✅ Lower heating bills
✅ Improved indoor air quality
✅ Supports sustainability and energy efficiency

Frequently Asked Questions (FAQ)

Q: Can I retrofit an MVHR system in an existing home?
Yes — but it’s easiest during renovations when you can install ductwork discreetly in ceilings or walls.

Q: Does MVHR work in summer?
Yes. Most systems include a summer bypass mode, allowing cool air in without heat recovery.

Q: Is MVHR noisy?
Not if installed correctly. Using acoustic ducts and silencers ensures near-silent operation.

Final Thoughts

Installing an MVHR ventilation system is one of the smartest upgrades you can make to your home or business. It delivers fresh air, consistent temperatures, and long-term savings — all while reducing your carbon footprint.

At Ventilation Superstore, we offer a complete range of MVHR units, ducting, filters, silencers, and accessories — everything you need to install your system with confidence.

👉 Explore our MVHR range and start building a cleaner, more comfortable space today.