Do All MVHR Systems Require a Defrost Unit?

Unbeknownst to some, your MVHR unit has the capacity to be affected by freezing temperatures, this can result in a reduced efficiency, or even serious technical issues for your MVHR unit.

With that being said, is there anything that can prevent it? Either within or separate from the MVHR system?

In this blog, we will address the question ‘Do all MVHR systems require a defrost unit?’

With new buildings being made to be as energy efficient as possible, and the UK aiming for 95% of its electricity usage to be low carbon by 2030, it is imperative to understand how we can make the most of our ventilation. This is where MVHR units come in.

To prevent mould, fresh air should constantly be introduced into your dwelling daily, as it helps to regulate temperature and reduce condensation. Introducing fresh air can be as simple as having a ventilation routine, or installing extractors or MVHR units. Almost all of this is facilitated by ducting.

Do you need ventilation in cold weather?

Although a winter breeze is generally less pleasant than a summer’s breeze, you should know that regardless of the time of year, ventilation is needed in your home all year round.

Neglecting ventilation on hot days can result in a home that is uncomfortably hot, the air can also become stuffy and stale. When it comes to cold days, humidity and condensation develops at a faster rate in an unventilated hot home, simply due to the contrasting outdoor temperature.

As a result of neglecting ventilation on a cold day, the dwelling in question may end up being susceptible to mould growth.

Mould is a potentially dangerous form of fungus that thrives in humid environments, it can develop in any room, but is commonly found in bathrooms and kitchens. Mould has the potential to cause or exacerbate health conditions. It should be removed wherever possible.

How do I prevent mould in my home?

Common methods of mould prevention in a home can be achieved through the following suggestions…

• Opening windows regularly, especially in bathrooms and kitchens when you are using them.
• Invest in, or update, your extractor fans/MVHR systems.
• Remove any existing mould in the home.
• Address any issues that can cause mould, like leaking pipes, or unsecure windows and doors that let drafts into the home.

What is MVHR?

MVHR stands for ‘Mechanical Ventilation with Heat Recovery’. This is the formal term, the units that use this technology are generally known as heat recovery units, or heat recovery systems.

As the name suggests, MVHR units provide the function and benefits of ventilation, whilst also finding a way to recover heat that is lost during ventilation. They are available in single or multi-room units.

The advantages of heat recovery systems are the following:

• Holds all the benefits of an extractor, including the removal of stale air, humidity and smells.

• It helps to prevent the cultivation of mould through the removal of humidity.

• Temperature sensors ensure that additional heat is not being added to the atmosphere of the home if it is already hot.

• Heat recovery systems take a lot of the burden from you conducting a ventilation routine. This is ideal for a vulnerable person.

• Less of a need to use your central heating frequently as the heat generated through your house is recycled through the heat recovery unit.

• The reduced use of heating as a result of the heat conservation granted by a heat recovery unit can help you save on energy bills.

Do all MVHR systems require a defrost unit?