Woodgnome Posted November 11, 2017 Share Posted November 11, 2017 Has anyone got an MVHR comissioning Spreadsheet or form which would be suitable to give to BC for Building Regs. Not sure how much info they require apart from the room extract flow rates and whole house ventilation rate. Thanks Link to comment Share on other sites More sharing options...
Jeremy Harris Posted November 11, 2017 Share Posted November 11, 2017 Mechanical Ventilation and Heat Recovery system Test Report.pdf This is what I did and BC had no problem with it at all. It's not 100% in accordance with the guidance note for Part F https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/456656/domestic_ventilation_compliance_guide_2010.pdf , but that didn't seem to matter, as they thought that it adequately addressed every requirement. 1 Link to comment Share on other sites More sharing options...
Woodgnome Posted November 11, 2017 Author Share Posted November 11, 2017 Thanks Jeremy. Does the velocity need to be shown for BC? Link to comment Share on other sites More sharing options...
Jeremy Harris Posted November 11, 2017 Share Posted November 11, 2017 29 minutes ago, Woodgnome said: Thanks Jeremy. Does the velocity need to be shown for BC? No, all they need is evidence that the flow rates for the defined extract rooms (kitchen, bathrooms, utility room, WCs) meet the requirements in the table in Part F, and also that the whole house ventilation rate meets the requirement. Link to comment Share on other sites More sharing options...
Woodgnome Posted November 12, 2017 Author Share Posted November 12, 2017 Do I need to incorporate " Purge" ventilation figures. Ie..door and window openings, or is that part just for Basements in Part F? Link to comment Share on other sites More sharing options...
Jeremy Harris Posted November 12, 2017 Share Posted November 12, 2017 (edited) If you have MVHR, then you only need to comply with the MVHR parts, i.e. what they call "whole dwelling ventilation". If the MVHR is turned off for a long period, then the recommendation is that you set it to boost for a short time when switched back on in order to provide the required purge ventilation. Edited November 12, 2017 by JSHarris Link to comment Share on other sites More sharing options...
Woodgnome Posted November 12, 2017 Author Share Posted November 12, 2017 Thanks Jeremy. Link to comment Share on other sites More sharing options...
HerbJ Posted November 13, 2017 Share Posted November 13, 2017 Hi I had a fairly large system designed, installed and commissioned by Paul Scotland. I attach their MVHR Commissioning Report submiited to BC. I had no questions... 38167 East Croft Comm Report_20160818.pdf Link to comment Share on other sites More sharing options...
Woodgnome Posted November 16, 2017 Author Share Posted November 16, 2017 (edited) Struggling to get my head around the set up. My minimum whole house Supply low rate is 49l/s Minimum extract high rate ( boost) is 43l/s So if I put the unit on boost to adjust the extract valves to get the required rate in each room, which will be a minimum total of 43l/s ..then whilst still on boost do the same for the supply valves to get as close to the extract rates as I can to balance the system. Then...my minimum whole house Supply rate is 49l/s...which is more than my minimum extract on boost. I will already have close to that figure as I will have hopefully already balanced it on boost to get to the minimum extract ( boost) rate. In this case do I have to have way over regs required for my flow rates on my boost settings? So once i go back on normal rate, I can achieve my minimum Supply rate for the dwelling on normal rate whilst keeping the extract and supply rates balanced. Vent Axia unit...current settings for fan speeds are 30% normal supply and 50% boost, but can be adjusted. Thanks. Edited November 16, 2017 by Woodgnome Typo Link to comment Share on other sites More sharing options...
le-cerveau Posted November 16, 2017 Share Posted November 16, 2017 The issue is that the Building Regs are based around standard homes, as soon as you build a big (non standard) house they struggle. You have a large house so your whole house supply rate exceeds any extract requirements so you will always be extracting above the boost rate! (system balanced). One the system is certified you can always re-adjust, as many here do, but to pass inspection your system has to supply the house (and extract in a balanced system) at the largest number! Link to comment Share on other sites More sharing options...
Jeremy Harris Posted November 16, 2017 Share Posted November 16, 2017 As above, for a lot of houses the background rate in the regs is higher than the other rates. If you actually ventilate at the building regs background rate then you will probably find, as we, and others, have that the ventilation rate is too high. I don't know where BRE came up with the background ventilation rate, but it does seem to be much higher than the normal ventilation rates in non-MVHR houses, and higher than most feel comfortable with in a house with MVHR. Link to comment Share on other sites More sharing options...
Bitpipe Posted November 16, 2017 Share Posted November 16, 2017 13 minutes ago, JSHarris said: As above, for a lot of houses the background rate in the regs is higher than the other rates. If you actually ventilate at the building regs background rate then you will probably find, as we, and others, have that the ventilation rate is too high. I don't know where BRE came up with the background ventilation rate, but it does seem to be much higher than the normal ventilation rates in non-MVHR houses, and higher than most feel comfortable with in a house with MVHR. I proved through measurement that we meet the whole house extraction rate and noted the fan settings to achieve that (plus the other compliance. When I have my final inspection, I'll set the fan speeds accordingly and show my inspector if necessary. Then I'll put them back to where they are today. Link to comment Share on other sites More sharing options...
Woodgnome Posted November 16, 2017 Author Share Posted November 16, 2017 (edited) Thanks, so when I start to set it all up...i set my boost ventilation rates to be well in excess of BC requirements...then put the unit on normal rate and adjust to get my whole house minimum Supply rate.( which happens to be more than my minimum extract on boost). Once I've balanced the normal rate..and BC are happy, people usually turn down the fan speeds on normal rate due to the numbers in the regs being in excess of whats required when you are actually living in the house? Edited November 16, 2017 by Woodgnome Link to comment Share on other sites More sharing options...
Paul_c Posted February 17, 2018 Share Posted February 17, 2018 Hi, I’m in Conwy, North Wales. I installed a Villavent vr400 dc system in my new build home, a few years ago. As money had run out and just needed to move in, I set all the ceiling terminals to about half and switched on. i now need a commissioning certificate, to get my final ticket, from building control. PLEASE can any one help me either ‘fudge’ a certificate or point me towards someone local’ish ,that knows what there doing. I really haven’t a clue! Thanks for any help. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 17, 2018 Share Posted February 17, 2018 You can DIY it. It's a bit tedious, but not technically that difficult, and there is nothing in Part F that requires that the person doing the commissioning and producing the report needs any particular qualification or accreditation. The forum has two air flow meters available to loan out, in return for a modest donation to the forum running costs. Unfortunately, in order to see that section you need ten posts here, just as a safeguard, really, as the kit has been donated and isn't that cheap. Alternatively, you can hire the air flow meters, I believe. The guidance note I linked to earlier in this thread is a reasonable starting point, but I failed to find it when I was looking for help on how to set the system up, so I made up my own report format, again there is a link to that in the second post in this thread. If you don't want to DIY the commissioning, then really your only alternative is to try and find a HVAC (heating, ventilation and air conditioning) contractor in your area that can do it. All HVAC contractors will have the required flow meter, and know how to use it, and even if they are not familiar with MVHR, showing them a copy of the guidance note on commissioning should enable them to do the job. I would guess that you would be looking at the best part of a day's work to do the commissioning, could be less, it really depends on how much running around has to be done. The process is iterative, as every time one terminal is adjusted it tends to change the pressure and so affect the flow at all the other terminals on that side of the system. Link to comment Share on other sites More sharing options...
le-cerveau Posted February 17, 2018 Share Posted February 17, 2018 I have just finished doing my commissioning myself, 36 terminals, 6 cisterns (connected to the system) and 43 ducts with restrictors (Ubbink system). Full details on my blog will be doing another entry about the commissioning in due course. 3 days work including the final connecting up of the external ducts, powering up the units etc. I used a direct copy of Section 5 of the attached (Domestic Ventilation Compliance Guide), just created a copy on Word and used that with a system description at the start. Waiting to see that it will be accepted. domestic_ventilation_compliance_guide_2010.pdf Link to comment Share on other sites More sharing options...
Woodgnome Posted February 20, 2018 Author Share Posted February 20, 2018 If its any help...my BC didnt ask for the comissioning certificate. Link to comment Share on other sites More sharing options...
Saz123 Posted July 24, 2019 Share Posted July 24, 2019 Hi I am currently writing up my own report and wondering if I have been asked for air flow rate/ extract rate certificate in accordance with part f by BC then will i need to work out and measure whole house ventilation rates or simply just test the fans in bathroom and cooker hood? I have been using the guidance document to write up my readings that i took with a testo 417 that i borrowed, but i am not sure if i should fill in and submit parts 1,2 and 3 or just keep it simple and give them part 3 - the flow rate measurements for bathroom and kitchens. Its for a conversion i am doing and they asking for it as the said it classed as new dwellings. I have look through some of the great stuff already on here but any other help would be amazing. I am a bit confused about the reference to whole house ventilation......do i need to include that or is that for when they ask you to do air tightness testing for part L? I think i managed to calculate the background ventilators and worked of the table to ensure they match the minimum required, so that was OK, i did it of the trickle vents in the windows and brick air vents in the walls. I am struggling to find examples of domestic air flow rate certificates. I found a few companies who can come and do it for me but i figured seeing as i could borrow the machine and do my self i would rather just right up my own report and see if BC except that? Also another bit that i was unsure about was a few comments that a certificate is required for each dwelling? Is that just a money making ploy and can i simply fill al the readings for both flats in the house on one report? Link to comment Share on other sites More sharing options...
Jeremy Harris Posted July 24, 2019 Share Posted July 24, 2019 Welcome. My experience (MVHR, new build) was that building control weren't really bothered, they just needed a bit of paper to tick the box. I wrote a report for our system, with measured flow rates, but frankly they weren't really interested in the content at all. Best bet might be to just ask what they want, as that way you won't waste time writing up stuff that they aren't interested in. Link to comment Share on other sites More sharing options...
Saz123 Posted July 24, 2019 Share Posted July 24, 2019 (edited) Hi JS thanks for the speedy reply.....i saw your report it was great. I spent last three days lol writing up mine but what i have so far but am just got a bit thrown by the whole house ventilation bit. I used system one in the flats and followed the checklist in the document guide and work out all the background ventilator bits.......its the last bit the said they want then apparently i can get sign off. Fingers cross. I just dont want more agro they put me through the ringers for the last year! You know that last hurdle and your like omg please just let me get over this last one. This is what i have done so far and was just thinking to put in my electricians details for the installer bit and myslef for the test engineer ? Part F Airflow v2.docx Edited July 24, 2019 by Saz123 Link to comment Share on other sites More sharing options...
Jeremy Harris Posted July 24, 2019 Share Posted July 24, 2019 8 minutes ago, Saz123 said: Hi JS thanks for the speedy reply.....i saw your report it was great. I spent last three days lol writing up mine but what i have so far but am just got a bit thrown by the whole house ventilation bit. I used system one in the flats and followed the checklist in the document guide and work out all the background ventilator bits.......its the last bit the said they want then apparently i can get sign off. Fingers cross. I just dont want more agro they put me through the ringers for the last year! You know that last hurdle and your like omg please just let me get over this last one. This is what i have done so far and was just thinking to put in my electricians details for the installer bit and myslef for the test engineer ? Part F Airflow v2.docx 73.59 kB · 0 downloads That looks OK to me, there's no requirement for any specific competence for someone signing of a Part F chit, so just your signature should be fine. Link to comment Share on other sites More sharing options...
Saz123 Posted July 24, 2019 Share Posted July 24, 2019 ok thanks lets submit and il let you know how it goes fingers x ? Link to comment Share on other sites More sharing options...
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