MVHR – What is MVHR?

An MVHR System (Mechanical Ventilation with Heat Recovery) is a whole house ventilation system for modern, energy efficiency homes.  The MVHR unit works continuously in the home by extracting stale, moisture and pollutant laden air from the wet rooms in the home and at the same time supplying fresher air to living and bedrooms.  As air is extracted, up to 95% of the heat is recovered in a heat exchanged inside the unit and re-used for the supply air.  This helps keep the internal environment comfortable and efficient.  When the outside air temperatures increases, the heat recovery mode is turned off to avoid overheating and increasing the internal temperature.  This is called the summer by-pass mode and is usually pre-set on the machine to happen automatically. A MVHR unit is usually installed in a cupboard, utility or loft space.  Ceiling mount options are also available which can be concealed in the ceiling void.

What are the benefits of MVHR?

MVHR ventilation systems provide many benefits to todays modern energy efficient homes.

• An MVHR System helps maintain a good level of indoor air quality in the home – good for allergy sufferers and those with respiratory conditions, as well as the health and well-being of your family
• An MVHR System helps eliminate issues with condensation and mould and maintain a comfortable environment free from moisture and humidity
• An MVHR Systems helps reduce your heating bill be recovering and reusing heat throughout the ventilation process

 How do I control MVHR Systems?

There are many MVHR Heat Recovery Systems available on the market for varying property sizes and with a range of different controls.  It is very simple to operate your MVHR heat recovery system throughout the year.

 An MVHR Heat Recovery system runs 24 hours per day on trickle and boost speeds.

The trickle speed runs continuously throughout the day and night.

The boost speed increases the rate of ventilation when activities such as cooking and showering take place.
The boost can be activated via:

1. Manually via a switch
2. Automatic sensing – e.g. via humidity rises (from a shower)
3. Automatic Activation – e.g. via a bathroom light switch

How do I maintain a MVHR System?

A MVHR unit moves air in and out of your home 24 hours per day.
Over time, the system gets clogged with dust and debris which can start to impact performance and cause issues such as condensation and an environment that feels ‘stuffy’. This might also lead to increased levels of noise from the system itself. Servicing of your MVHR Heat Recovery System is recommended annually and MVHR Heat Recovery Filter Replacement is recommended to be checked/replaced every 6 months