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Hi, I have installed a Villavent mhvr system in my new build a few years back and it’s been running fine.

I never got my final ticket, due to a lack of funds and had to just move in. I now desperately need my final ticket , so I can try to claim vat back.

 

Do any of you clever people know the cheapest, easiest way for me to get a commissioning certificate passed on my system for building control.

Im in Conwy, N.Wales.

Appreciate and look forward to any help.

Thanks Paul

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Do it yourself, you will need to borrow / hire an airflow meter. I got a blank form from my supplier which I filled, signed and submitted.

 

Do you have target flows for each vent? This should have been calculated during design.

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6 minutes ago, PeterW said:

@JSHarris posts a spreadsheet a while back that he produced to do this from memory. 

 

I thought I had too, but I can't seem to find it in my attachments here.  I've found the copy on my machine, though, so here it is: Ventilation calcs.txt

 

Download it and rename it, replacing the .txt suffix with .xls (the forum doesn't like Excel files!)

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That’s great thanks, is there any chance you could forward it to (email address redacted) ? I'm on iPad and it's not cooperating many thanks

 

Edited by JSHarris
redacted email address to prevent spam!
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No problem, hope it makes sense.  I wrote the original so long ago that I'd have to take a look at it to try and recall what I did!

 

The main issue is that the flow meters indicate velocity, and don't really have an accurate enough flow rate setting (at least the Testo doesn't).  That means you need to quickly be able to convert the flow velocity you measure over a specific area (in my case I used a 100mm diameter tube, with a cone to push up against the ceiling terminals) into the flow rate in litres/second.

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38 minutes ago, JSHarris said:

 

The main issue is that the flow meters indicate velocity, and don't really have an accurate enough flow rate setting (at least the Testo doesn't

I bought a Testo 405i a few months ago and have been using it over the last few days to set up our system. It allows you to input the diameter of the tube that the sensor is in and it calculates the volume and lists that and the velocity and temperature.

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1 minute ago, PeterStarck said:

I bought a Testo 405i a few months ago and have been using it over the last few days to set up our system. It allows you to input the diameter of the tube that the sensor is in and it calculates the volume and lists that and the velocity and temperature.

 

 

I had older version of the Testo 405, but when I put in the cross sectional area of the measurement tube it would only give flow rate in m³/hr, so the resolution wasn't good enough. Does the newer version have the option to change the units to l/s?  If so that makes it a lot more useful.

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10 minutes ago, JSHarris said:

 

 

I had older version of the Testo 405, but when I put in the cross sectional area of the measurement tube it would only give flow rate in m³/hr, so the resolution wasn't good enough. Does the newer version have the option to change the units to l/s?  If so that makes it a lot more useful.

I think I misunderstood what you were saying. No it still calculates the flow rate in m³/hr. So did you calculate the flow rate in l/s from the velocity.

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5 minutes ago, PeterStarck said:

I think I misunderstood what you were saying. No it still calculates the flow rate in m³/hr. So did you calculate the flow rate in l/s from the velocity.

 

Yes, I did.  I used the Testo to measure the velocity in m/s and then converted it using that spreadsheet.  Part of the reason for writing the spreadsheet was so I could take my small notebook PC around as I took the measurements and just enter the flow velocity and get the flow rate in l/s, to see if it passed or failed the requirements in Part F.

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