Decentralised Mechanical Extract Ventilation, or DMEV, is a 21st century solution to ventilation. Developed to address the need for efficient and localised ventilation in modern buildings, DMEV fans offer flexible installations and low running costs in single self-contained units.
This guide will explore how DMEV fans work, their key components, operating principles and what you should keep in mind when deciding if they are right for your home.
What are the components of a DMEV fan?
One of the key selling points of DMEV fans is their continuous yet energy-efficient operation, which is possible thanks to the interplay of several key components.
- Fan Unit - At the core of every DMEV fan is its main housing and motor, carefully designed to constantly run at low speeds. This is done through the use of brushless DC motors, robust materials like ABS plastic and stainless steel, and streamlined designs with very few moving parts. Critical components are typiclaly sealed or encapsulated to protect against moisture ingress or rust, further lengthening the lifespan of the fan.
- Sensors - Many DMEV fans come equipped with sensors to enhance efficiency and automation. The most common types are humidistats and motion sensors, adjusting the fan speed when the room is in use and winding back to the standard ‘trickle’ speed when not in use. This serves to maintain optimal indoor air quality (IAQ) and comfort without wasting energy.
- Control Mechanisms - DMEV fans typically incorporate simple switches or pull cords to adjust the fan’s operation as needed. Some fans come with programmable timers so they can continue running for a set period after a sensor is triggered, making sure moisture and odours are fully extracted.
How does a DMEV fan operate?
A continuously-running fan means a constant circulation of air throughout the targeted room.
Stale, humid and polluted air indoor air is continuously drawn in. Depending on the exact model of the DMEV, this is then passed through a series of filters to remove contaminants, separated using centrifugal force or expelled to the outside with high-velocity airflow. Vent Axia's Revive and Response ranges, for example, use innovative Multi-Vortex technology to expel dust without the need for a filter.
At the same time, fresh air is drawn into the room through vents, trickle vents or natural openings in the building. This has the dual effect of balancing the air pressure and maintaining a comfortable indoor climate. This constant ventilation means moisture doesn’t have a chance to accumulate and develop into more serious issues like black mould, while overall IAQ is improved due the removal of pollution and allergens.
Thanks to their sturdy yet energy-efficient construction, this is all done while consuming minimal power - A higher-end 5W DMEV fan will cost approximately £11 to run 24/7 for a whole year, while a standard 40W bulb used for just 5 hours a day will cost you over £18 per year!
How can you decide if a DMEV fan is right for you?
The fact that DMEVs operate on a per-room basis means they can be selected to serve specific needs.
- How humid is the room? - DMEV fans are often more effective than standard intermittent fans for preventing mould, condensation and moisture buildup. This makes them particularly suited to bathrooms, wet rooms and kitchens.
- Are you concerned about indoor air quality? - If you or somebody in your household suffers from allergies or sensitivities, a DMEV fan can work to remove allergens like pollen, dust and pet dander from the air.
- How has the building been constructed? - Newer buildings tend to be airtight and well-sealed, which makes them more energy efficient at the cost of natural ventilation. One or more DMEV fans can therefore go a long way to improving IAQ.
- Is noise a concern? - While most standard fans are designed to be quiet, the noise level can vary and tends to be more noticeable if they are only activated intermittently. DMEVs, on the other hand, are engineered to operate quietly, making them suitable for use in offices, bedrooms and other areas where noise might be an obstruction.
If you want to find out more, we've written a quick guide on the benefits of DMEV fans.
In conclusion, a DMEV fan works by constantly extracting stale indoor air from a given room and replacing this with fresh outdoor air. Their sturdy construction and energy-efficient designs mean this is achieved without excessive energy costs or disruptive noise.
Electricpoint stock a wide range of DMEV fans from leading brands, with models for every budget and need. If you would like any further help, please feel free to contact our friendly team for some expert advice on 0203 994 5470, drop us an email at sales@electricpoint.com or use our Contact Form.