Continually Running Ventilation

Continually Running Ventilation: MEV and dMEV – The Ultimate Guide

Maintaining indoor air quality is crucial for promoting health, comfort, and energy efficiency in any building, whether residential or commercial.

Continually running ventilation systems such as MEV (Mechanical Extract Ventilation) and dMEV (Decentralised Mechanical Extract Ventilation) provide a steady flow of fresh air while removing stale air, excess moisture, and indoor pollutants. These systems operate quietly and efficiently, complying with UK Building Regulations Part F (Ventilation) and Part L (Conservation of Fuel and Power). They are an excellent solution for new builds, self-build projects, and retrofit installations.

What is Continually Running Ventilation?

Continually running ventilation systems ensure constant air extraction, maintaining a comfortable and healthy environment by removing pollutants and excess moisture. Operating at low speeds, these systems prevent issues like condensation, mould, and poor indoor air quality.

Types of Continually Running Ventilation:

• MEV (Mechanical Extract Ventilation): A centralised system that extracts air from multiple rooms through a ducted network.
• dMEV (Decentralised Mechanical Extract Ventilation): A decentralised system designed for room-specific ventilation.

Both systems play an essential role in maintaining air quality and energy efficiency, ensuring compliance with building regulations.

MEV (Mechanical Extract Ventilation)

What is MEV?

Mechanical Extract Ventilation (MEV) is a centralised system that extracts stale air from multiple rooms (usually wet rooms such as kitchens and bathrooms) using a ducted network connected to a single fan unit. The extracted air is expelled outside, and fresh air enters through trickle vents or other passive inlets, maintaining a balanced airflow throughout the property.

Why Choose MEV?

MEV is ideal for larger homes, self-build projects, and commercial buildings where centralised control is essential. This system allows comprehensive management of air quality across multiple rooms, making it highly effective for properties requiring large-scale ventilation.

Key Features and Benefits of MEV:

• Whole-house ventilation: Suitable for larger properties and buildings.
• Energy efficiency: Reduces heat loss, lowering energy consumption.
• Customisable airflow control: Allows for demand-control options based on room conditions like humidity.
• Building regulations compliance: Fully compliant with Part F and Part L of the UK Building Regulations, ensuring optimal air quality and energy performance.

Installation and Customisation

MEV systems offer flexibility in installation with both continuous and demand-controlled ventilation options. Demand-controlled MEV systems adjust airflow based on real-time conditions, such as humidity or occupancy, optimising energy usage. MEV is ideal for new builds, major renovation projects, or retrofit installations where ductwork can be easily integrated.

dMEV (Decentralised Mechanical Extract Ventilation)

What is dMEV?

dMEV is a decentralised system designed to ventilate individual rooms, typically wet rooms like bathrooms and kitchens. Each room is equipped with its own fan, which runs continuously at low speeds to remove stale air effectively.

Why Choose dMEV?

dMEV is perfect for smaller homes, flats, or projects where room-specific ventilation is required. The decentralised design allows for targeted control of moisture and pollutants in specific rooms, eliminating the complexity of centralised systems. dMEV is cost-effective, energy-efficient, and simple to install, making it a great choice for retrofit projects and self-builds.

Key Features and Benefits of dMEV:

• Room-specific ventilation: Provides effective moisture control for areas like bathrooms and kitchens.
• Energy-efficient and quiet: Operates continuously at low speeds to ensure minimal energy consumption and quiet operation.
• Ideal for retrofits: Requires no complex ductwork, making it a great choice for both new builds and renovation projects.
• Compliance with regulations: Fully compliant with UK Building Regulations Part F and Part L, ensuring proper air quality and energy efficiency in individual rooms.

Installation and Versatility

dMEV systems are easy to install, particularly in retrofit scenarios where ductwork is not feasible. They are also ideal for new builds. Maintenance is minimal, typically involving occasional cleaning of fans or replacement of filters.

MEV vs dMEV: Which is Right for Your Property?

Choosing between MEV and dMEV depends on your property’s size, layout, and specific ventilation needs:

• MEV: Best suited for larger homes, self-builds, or commercial properties where a centralised system can provide comprehensive ventilation across multiple rooms.
• dMEV: Ideal for smaller homes or projects requiring room-specific ventilation. Its simplicity and ease of installation make it perfect for retrofitting, especially in areas that need targeted moisture and pollutant control.

Frequently Asked Questions (FAQs)

1. What is the difference between MEV and dMEV?

MEV is a centralised system that extracts air from multiple rooms via a ducted network, while dMEV is a room-specific system with individual fans for targeted ventilation in each room.

2. Which system is more energy-efficient, MEV or dMEV?

Both systems are energy-efficient, but MEV is better suited for larger properties where centralised control is more effective. dMEV is ideal for smaller homes or projects with localised needs.

3. Are MEV and dMEV compliant with UK Building Regulations?

Yes, both systems comply with UK Building Regulations Part F (Ventilation) and Part L (Conservation of Fuel and Power), ensuring energy efficiency and proper indoor air quality.

4. Can MEV and dMEV be installed in retrofits?

Yes, dMEV is particularly suitable for retrofit installations due to its simple setup, while MEV can be installed in retrofits if ductwork can be accommodated.

5. Are MEV and dMEV systems noisy?

Both systems are designed for quiet operation. dMEV runs continuously at low speeds and is especially quiet, while the noise level of MEV depends on the installation and fan type.

6. Can MEV or dMEV help reduce energy bills?

Yes, both systems are designed to be energy-efficient. MEV minimises heat loss during ventilation, and dMEV operates at low speeds, consuming minimal electricity. Both comply with Part L of the UK Building Regulations, ensuring efficient performance.

7. Are MEV and dMEV systems compatible with smart home technology?

Yes, many modern MEV and dMEV systems can be integrated with smart home systems. Demand-controlled ventilation (DCV) options allow for automation based on humidity, CO2 levels, or occupancy, and some systems can be remotely managed via smartphone apps or home automation systems.

8. How often do MEV and dMEV systems need maintenance?

MEV and dMEV systems require minimal maintenance, typically needing cleaning of fans and filters every 6 to 12 months. Regular maintenance ensures optimal performance and energy efficiency.

9. Do MEV or dMEV systems help with allergy control?

Yes, both systems improve indoor air quality by continuously removing allergens such as dust, pollen, and pet dander. MEV is particularly effective for homes with multiple rooms, while dMEV can target specific spaces where allergens are more prevalent.

10. Do MEV and dMEV systems improve humidity control?

Yes, both systems help regulate indoor humidity by continuously extracting moisture-laden air from wet rooms such as kitchens and bathrooms, preventing issues like condensation, mould, and damp.

11. What are the installation costs for MEV and dMEV systems?

Installation costs vary depending on the size of the property and system complexity. dMEV tends to be more cost-effective for smaller homes or retrofits, while MEV is typically more expensive due to the need for ductwork and centralised units.

12. Are MEV and dMEV systems eco-friendly?

Yes, both systems are eco-friendly, using energy-efficient fans and contributing to a lower carbon footprint by reducing the need for heating through efficient ventilation.

13. How long do MEV and dMEV systems last?

MEV and dMEV systems typically last 10 to 15 years or more, depending on maintenance. Regular cleaning and servicing help extend their lifespan.