What Is MVHR Commissioning?

What Is MVHR Commissioning?

What Is MVHR Commissioning?

Installing a MVHR system is only half of the battle. Especially if you don’t have your system installed by an expert, you can find yourself dealing with issues down the road. MVHR systems must be commissioned in order for you to have one.

That’s why in this blog, we will address the question ‘What is MVHR commissioning?’

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.

The basics of 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:

  • 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.

What is MVHR commissioning?

What is MVHR commissioning?

MVHR commissioning is the process of having your MVHR system tested to ensure it is balanced. MVHR systems operate differently depending on the dwelling they are placed in, as well as the size of the rooms and more, which is why commissioning is required.

A further reason for MVHR commissioning is to ensure the system meets ‘part F’ of UK building regulations. ‘Part F’ is a regulation based on ventilation requirements to maintain indoor air quality.

There are two parts to this regulation. Part 1 relates to dwellings, part 2 relates to buildings other than a dwelling. MVHR commissioning can be performed by anyone with the relevant certification, which in most cases is a ‘BPEC’.

Passing the commissioning process is as simple as ensuring that your unit meets the minimum ventilation requirement for the dwelling it is in. However, failure to get your unit commissioned, or failing the commissioning process will result in the following…

Failure to commission the unit:

You may experience the following issues by not commissioning your MVHR unit…

  • The unit is too loud.
  • The unit is not balanced.
  • Chances of moisture appearing in the vents.
  • The system is too strong or weak for the area dwelling it is in.
  • You won’t get the full benefits of the MVHR system.
  • You could be wasting more money to run the system as it isn’t balanced.
  • Chances of ceiling damage.
  • Chances of mould appearing.

Failure to pass the commissioning process:

Failure to pass the commissioning process may result in…

  • Removal of your current MVHR unit.
  • Guidance on how to rectify the situation before re-testing
  • Reinstallation of your MVHR unit or certain parts of it (vents).
  • Delays in completion meaning the dwelling can not be lived in until it is sorted.
  • More money spent through re-testing.

So now we know why the commissioning takes place, what is the process of MVHR commissioning?

The process of MVHR commissioning

The process of MVHR commissioning

After installing your MVHR system, the next step is to get it commissioned. The point of commissioning is to get the best possible performance from the MVHR unit, this means the best possible airflow, with as little noise as possible, and the greatest efficiency, thereby ‘balancing’ your system.

This is done by adjusting the fan speed of the unit in accordance with the altering flow rate that passes through the air valves. This process is made easier by measuring the relevant factors though a tool called an anemometer.

The anemometer tests each valve whilst adjusting it and the whole MVHR unit, in accordance with the unit’s specification and design. After the appropriate airflow rates have been set in the unit, the valves are locked into position to maintain that rate, which is then recorded onto a form and inspection checklist for building control.*

*Building control is a government body (usually under the remit of your local council) that ensures building regulations are being met.

The form has three parts:

  1. Details of the MVHR system are recorded, as well as the address of installation, and installer’s details.
  2. Split into two subparts. 2A is an installation checklist, 2B records the outcome of the visual inspection.
  3. Part 3 is designated for recording the results of the mandatory air flow test. This part of the form will be requested by building control. Who will then approve your MVHR system if it is appropriate.

Who commissions MVHR?

There are many certified MVHR commissioners in and around the UK. The easiest method is a simple internet search for any in your locality. Alternatively, the installer of your MVHR system may themselves have contacts that commission MVHR too, so asking them is the best way forward.

Do not get your MVHR system commissioned from anyone who is not BPEC certified, or holds any such relevant qualification. We at I-Sells deal with all things ventilation, so if you’re really struggling to find a verified MVHR commissioner, get in touch with us, and we will attempt to help you find one.

Do all MVHR systems need commissioning?

No, only whole-house units. Single-room MVHR systems don’t need to be commissioned, but must still be installed correctly, so they are balanced.

Do I need MVHR?

Below are some signs that indicate that a MVHR system is a worthy investment for your home. These signs are…

  • Your home or certain rooms feel humid all of the time.
  • There is mould present in certain areas of your home.
  • Heat escapes the house quickly when using ventilation.
  • The air in your home isn’t fresh/ has dust present.

MVHR system cost

The cost of MVHR systems vary between the type of MVHR unit you require. Naturally, single-room units will cost less than whole-house units. Our range of MVHR units begin from just over £260, to over £3000.

Click here to view our full range of MVHR units.

Purchase a MVHR system today

Purchase a MVHR system today

We at I-Sells endeavour to ensure our customers have all the information they require before investing in our mould solutions. Be sure to visit our blog page to learn about the vast array of factors and issues surrounding ventilation, mould, condensation, and much more.

We hope to have answered the question ‘What is MVHR commissioning?’

We understand you may have more questions, do not hesitate to contact us for more information about whatever you need our help with. If you’d like to send us an email, click here. For other contact options, see below:

Call us on 020 8463 9696

Visit us at our showroom:


Monday – Friday: 8:00 am to 5:30 pm

Saturday: 9:00 am to 12:00 pm

Sunday: Closed

15 St John’s Parade

Sidcup, Kent

DA14 6ES

United Kingdom

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