Multiple Input Ventilation (MIV®)

Building on the principles of the hugely successful and established EnviroVent PIV systems, the MIV® Loft Mounted Unit has been designed and developed to launch a totally new and innovative technology – Multiple Input Ventilation (MIV®).


Energy Saving Benefits

Minimum Energy Consumption

Powered by an Ultra Low Watt Brushless DC Motor, the MIV® Loft Mounted Unit utilises the latest technology to ensure minimum energy consumption and long term trouble free life.


Solar Gain

The unit takes maximum advantage of the benefits of solar gain from within the loft space – the natural accumulation of heat from the sun on bright days. Temperatures in the loft space are on average 3°C higher than outside, which results in a relative saving of around 150 Watts per day in an average modern family home. This equates to approximately 10% of annual heating costs.


Heat Distribution

Warm air accumulates at ceiling level. This air can be up to 7°C higher than the internal air at ground level. By introducing an almost imperceptible air supply into the dwelling from the loft space, the MIV® Loft Mounted Unit helps to redistribute heat around the home and thus reduce space heating costs.


No Need To Open Windows

To reduce humidity and condensation during the heating season, significant energy loss occurs by opening windows. By installing an EnviroVent MIV® Air Source and providing fresh filtered air to the home humid air is displaced without opening windows and thus making significant savings to the occupier.


Health Benefits

With improved building features in our homes, such as cavity wall insulation, double glazing and draught proofing, ‘natural ventilation’ is prohibited. Stale air is trapped causing streaming windows, which ultimately leads to musty smells, dampness and mould growth. These mould spores are known allergens and become airborne at the slightest disturbance. The microscopic spores are then inhaled and can trigger respiratory problems such as asthma, dust allergies and hayfever.

The EnviroVent MIV® Loft Mounted Unit draws fresh air into the dwelling from outside and filters it before being delivered into the property. Moisture-laden air is diluted, displaced and replaced with clean, tempered and filtered air. This eliminates or reduces surface condensation, which causes mould growth, providing a significant improvement in the health of asthma sufferers and general indoor air quality.


  • Ultra Low Watt DC motor technology
  • Sealed for life ball bearings
  • Loft or external air supply
  • Integral Hours Run Meter (as standard)
  • Integral intelligent comfort heater (as standard)
  • Optional wireless boost facility
  • 5 Year guarantee


  • Provides all year round quality filtered air
  • Reduces/eliminates surface condensation
  • Quiet operation
  • Removes musty odours
  • Enhances heat distribution
  • Takes advantage of the benefits of solar gain in the loft space
  • Benefits asthma sufferers by reducing dust mites and mould spores
  • Reduces Radon levels
  • Easy to install


How is it different?

Instead of providing just a single source of fresh air into a property, usually located in a hallway or landing, the MIV® Loft Mounted Unit has the ability to supply fresh, filtered air via multiple inputs into areas with greater requirements for ventilation.

Highly efficient, inputs can be situated in rooms affected by increased levels of humidity, such as the kitchen, bathrooms and other wet rooms.

Fresh air inputs can also be located in bedrooms or living spaces that suffer from particularly bad condensation or in the bedroom of an asthma sufferer to reduce the level of humidity and therefore the house dust mite population – a known trigger for allergies and asthma.

MIV® Multi-Zone Destratification

Warm air accumulates at ceiling level and is normally lost through windows and extract fans. This air can be up to 7°C higher than the internal air at ground level. By introducing an almost imperceptible fresh air supply into multiple rooms, the MIV® Loft Mounted Unit redistributes heat around the home by pushing the heat back down and keeping the convection currents moving to reduce space heating costs. By saving only 1 degree of heat this multi-zone destratification can cut fuel bills by 10%.

Unique EnviroVent Mini Diffuser

Available with the MIV® Loft Mounted Unit is the stylish EnviroVent energy saving diffuser, providing an innovative alternative to standard ceiling vents. Simple to commission and install, the diffuser is designed with easy to clean filters, which prohibit contaminants entering the property. These also act as a second defence against some pollens and other airbourne contaminants in conjunction with the unit’s internal filter. Side panels can be easily blanked off according to its location.