Mvhr official testing

[Simon Brooke]

Hi,

After an initial visit when he seemed happy with my self certified testing of the mvhr flow rates, the building inspector has now written to say he requires a specialist to perform the tests. Has anyone come across this and is there a way round it?

Thanks,

Simon

[JFDIY]

Could you hire calibrated kit with proper funnels etc and range for him to view the test while you do it, if you set the syetem up before hand , prepare a compliance chart with expected flows of each room (and reference how each one meets the regs requirement) should only take an hour to prove it to them in person, tick each one off as you go through it.

 

[Bitpipe]

Write back and ask him to confirm the qualifications / professional industry memberships that the 'specialist' must have to satisfy him.

 

Did you use a calibrated bit of kit to do the initial testing & measure room flows against the regs? 

 

Most of us here wrote up a formal looking report and send that to our BI which satisfied them.

 

[MJNewton]

As above I'd ask him to define 'specialist'. Or tell him *you* are a specialist and leave it to him to say in what way he disagrees. Remember often they have to act in a way that demonstrates due diligence, and they may not need much from you to enable him to demonstrate he's done his job in terms of verifying compliance. 

[Simon Brooke]

Thanks. I used the group's Testo and actually asked the bco if this would be ok. He has now changed his mind! I will follow up on your suggestion.

[phatboy]

I would ask what professional qualifications he is looking for.  The answer will probably be 'there aren't any', in which case re-submit your results!

[joe90]

This was mentioned here before and I believe the upshot is there is no qualification, I believe @Jeremy Harris found this out. My BCO simply looked at the vents and said, you have MVHR so don’t need trickle vents or fans.  I copied Jeremy,s spreadsheet in case he needed docs but he did not even ask for it.

[SteamyTea]

Any help

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/456656/domestic_ventilation_compliance_guide_2010.pdf

[joe90]

5 minutes ago, SteamyTea said:

Any help

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/456656/domestic_ventilation_compliance_guide_2010.pdf

 

Only part that I can find relevant is :-

 

 signed by a person who is responsible for the inspection and testing of the system that has been installed.

 

and:-

 

Competent Person Scheme/ Registration Number (if applicable).

[joth]

1 hour ago, joe90 said:

there is no qualification

 

Qualifications do exist e.g.: https://bpec.org.uk/qualification/domestic-ventilation-systems/  (this is what our supplier/installer references on their certifications page)

AFAIK they're not recognized/required by any professional or statute body.

 

Edited December 11, 2019 by joth

[joe90]

This from building regs.

 

Responsibility for compliance
1.10 It is important to remember that if you
are the person (e.g. designer, builder, installer) carrying out building work to which any requirement of building regulations applies you have a responsibility to ensure that the work complies with any such requirement. The building owner may also have a responsibility for ensuring compliance with building regulation requirements and could be served with an enforcement notice in cases of non-compliance.

 

Also

 

(3) Where this regulation applies the person carrying out the work shall, for the purpose of complying with paragraph F1(2) or L1(b) of Schedule 1, give to the local authority a notice confirming that the fixed building services have been commissioned in accordance with a procedure approved by the Secretary of State.
 

 

Nowhere does it state the person commissioning should be qualified, like it does regarding electrics for example.

[Simon Brooke]

Thanks all. I am waiting for a response from the bco.

[Bitpipe]

Maybe we need to start a certification program -   BuildHub Ultimate MVHR Expert or BUM Expert for short.

[SteamyTea]

11 minutes ago, Bitpipe said:

BUM Expert 

BUM Blower.

[JamesP]

Advice please as just been sent this from the BC who mentions a specialist contractor required.  @Simon Brooke @joe90@Jeremy Harris

I installed the whole system and want to confirm that no legal requirement for a "specialist contractor"  to complete commissioning.

I plan to do the testing myself with the help of Jeremy's spreadsheet.

Thank you.

 

 

Air flow rate testing and commissioning of ventilation systems
4.42 The Regulations require:

• mechanical ventilation systems to be commissioned (where they can be tested and adjusted) to provide adequate ventilation and a commissioning notice to be given to theBCB; 
• air flow rates for mechanical ventilation systems in new dwellings to be measured and a notice to be given to the BCB. 

4.43 For dwellings, the procedures approved by the Secretary of State for measurement of air flow rates and for commissioning of mechanical ventilation systems are in Sections 2 and 3 of the Domestic ventilation compliance guide. Section 5 of the guide contains air flow measurement test and commissioning sheets which should
be completed by the person responsible for commissioning.

[joe90]

As far as I remember @Jeremy Harris established there is no “qualification” to make anyone a specialist contractor, you could ask the BC what qualification they require, my BC didn’t even ask (as I still have not balanced it yet ?)

 

 

Edited June 9, 2020 by joe90

[joe90]

10 minutes ago, JamesP said:

which should
be completed by the person responsible for commissioning.

does not say “qualified”

[joe90]

Just trawled through the doc @SteamyTea listed above and no where can I find a reference to a qualified person, nearest is “competent person (if applicable)” and I would suggest it’s not applicable and let the BCO prove otherwise.

[Simon Brooke]

It seems to me that bco's primary interest is to get a bit of paper on file and tick off that particular box. That said I must admit I struggled to get the system balanced and sought professional help. It turned out the planned figures calculated by the supplier were not achievable but for a couple of hundred quid I was reassured that the system was ok and the bco was also happy. In the scheme of the build I concluded the cost to be well worth it.

[Bitpipe]

Agree - for me, 'something' was needed to tick the box. Doubt it was ever looked at but it was sound.

 

18 minutes ago, Simon Brooke said:

It turned out the planned figures calculated by the supplier were not achievable but for a couple of hundred quid I was reassured that the system was ok and the bco was also happy. In the scheme of the build I concluded the cost to be well worth it.

 

I just used the numbers in the regs as the target to be hit vs anything that came from the supplier - i.e. min extract rates for kitchen/bathroom, overall balancing of intake and extract and the whole house ventilation rate (which for most of us was achievable but not comfortable - noted required settings and then dialled fans back to comfort level).

 

[MJNewton]

Is there a BR requirement for maximum ventilation? If not then just whack the system up to full and measure the flow rates to ensure the minimums are met and done with it. I doubt there's a need for a balancing for BR compliance too. 

Edited June 9, 2020 by MJNewton

[Bitpipe]

11 hours ago, MJNewton said:

Is there a BR requirement for maximum ventilation? If not then just whack the system up to full and measure the flow rates to ensure the minimums are met and done with it. I doubt there's a need for a balancing for BR compliance too. 

 

There is a minimum whole house ventilation rate that is presented as 0.3l/s/m2

 

So, like others, I calculated my total internal floor area in m2 and multiplied it by 0.3. I then calculated the total supply rate in l/s by summing all the flow rates as measured at each supply terminal and tweaked the fan supply speed until it met or exceeded the whole house ventilation figure.

 

From memory, first pass at the default 30% fan speed was about 0.25l/s so I cranked the fan up to 40% and that did the trick. Once that was established, I turned it back down to the 30% comfort level. 

 

Note that on my system (like many) the flow control is at each terminal so there is no alternative to running around and measuring each one every time you tweak the unit fan speed. That said, it only took a few hours to do the whole measurement exercise once I'd figured out how to get correct measurements.

 

TBH - this is the last test you want to do as prior to that, most of the effort was tweaking the supply and extract to balance the system (which should remain balanced irrespective of unit fan speed).

 

The extracts were all double ducted so easily exceeded the min extract rates.

 

To summarise, the only thing that BR cares about wrt MVHR is:

 

- has system been properly installed and checked - there is a tick list for this. Includes ensuring system is balanced.

- are min extract rates met for bathrooms, kitchens etc?

- can min whole house ventilation rate be met? (up to you if you keep these settings or revert to a lower comfort level).

 

This is what I included in my test report to my BC independent inspector.

 

[JamesP]

Thanks @Bitpipe that is just what I will provide to the BCO once I can confirm its ok for myself to complete the commissioning.

 

 

[Bitpipe]

20 minutes ago, JamesP said:

...once I can confirm its ok for myself to complete the commissioning.

 

Do you mean a) you're happy/ confident to do it yourself or b) you want their advance permission that you're ok to do it?

 

I would just tell them that you will provide a report that confirms MVHR commissioning & compliance to the regs. 

 

I would not view this as an  'asking permission' scenario as, unlike electrical or plumbing test certs there is no professional qualification or equivalent in existence for MVHR.

 

If you do ask, what's the plan if they say no?

 

[JamesP]

@Bitpipe I just emailed  them saying I would be providing the report as no qualification necessary. 

I have same Vent Axia, our floor area is about 290sqm though we have some high ceilings so might need to crank up the flow rate when commissioning.

Thanks for your help.