MVHR Vent Calculations Spreadsheet

[Triassic]

I've downloaded the Vent Calcs spreadsheet and I'm filling it in, however I'm unsure what the finished tables should look like. Would anyone be willing to share their completed spreadsheet?

 

Also, there is a long waiting list for the loan MVHR test equipment. Has anyone hired the equipment, if so, where from?

 

https://forum.buildhub.org.uk/applications/core/interface/file/attachment.php?id=23287

 

 

Edited November 8, 2022 by Triassic
Title missing and typo

[JohnMo]

Not the best spreadsheet for calculations.

 

Basically balance supply and extract.  Here is some guidance on flow rates.

 

It's a bit of a giggle to get thing matched up.  I found it easier to build my own sheet.

 

[Gone West]

I bought a Testo 405i and made a cone. https://www.test-meter.co.uk/testo-405i-bluetooth-thermal-anemometer

 

 

These are the results. I just made a table.

 

[Triassic]

In doing the calculations,  do I need to take air infiltration into account from the 2 x 150mm stove flue pipes ?

[JohnMo]

Are they stove connected ie sealed to the stove and open in the room?

[Triassic]

5 hours ago, JohnMo said:

Are they stove connected ie sealed to the stove and open in the room?

They are just two wood burning stoves, each with a stainless steel flue pipe?

[JohnMo]

Sorry miss read.  No you don't take into account the flue pipes, although I assume you have room sealed stoves, with an outside air supply direct to the stove, not air bricks to provide the combustion air.

[cwr]

On 09/11/2022 at 08:40, Gone West said:

I bought a Testo 405i and made a cone. https://www.test-meter.co.uk/testo-405i-bluetooth-thermal-anemometer

 

 

These are the results. I just made a table.

 

I'm intrigued by this, did it work well and cope with low velocities/air flows? 

[JohnMo]

I made a similar one.  Then had someone with certified equipment come and 'official' commission so I got a test cert with calibrated equipment certificate.  He remarked how close the initial setting were compared to final, I think one terminal was slightly adjusted.

 

So works well.

[Gone West]

3 hours ago, cwr said:

I'm intrigued by this, did it work well and cope with low velocities/air flows?

Yes it worked well. It sends the reading via bluetooth to an app on the phone and then I printed them out. It's just time consuming going round every vent and then repeating the process until it's all balanced.

[Tims]

You've just saved me question on making exactly the same test funnel with some leftover plenum pipe @Gone West. I've got an RS components hotwire bluetooth anometer on order from Ebay (£10.95 including postage and packing) that looks like it came from a bankruptcy auction of a contractors kit (has an asset number sticker on it). Hopefully all that is wrong with it is a missing battery compartment cover 🤞. I'll be happy to lend it to people if it works when I've finished my initial set up (though that's a while off yet). If it doesn't work how do you go about going on the waiting list for the forum one?

[MikeSharp01]

On 09/11/2022 at 08:40, Gone West said:

hese are the results. I just made a table.

 

 

How did you get away with less than the part F 4 ACH for the extract rooms?

 

[Gone West]

1 hour ago, MikeSharp01 said:

How did you get away with less than the part F 4 ACH for the extract rooms?

I did it twice, once for SAP and then the real settings for PH, which is what we kept. The BCO wasn't interested in the SAP results, so for me it was a waste of time.

[tuftythesquirrel]

On 08/11/2022 at 16:49, Triassic said:

I've downloaded the Vent Calcs spreadsheet and I'm filling it in, however I'm unsure what the finished tables should look like. Would anyone be willing to share their completed spreadsheet?

 

@TriassicHi, Made my own a while ago. Wanted to convince myself that my 690m3/h unit was big enough to do the job. So with my 750m3 house, running  at 0.5ACH (Scottish Regs.) the unit will be running at just over 50%.

 

When I asked our BCO whether we need a calibrated instrument to fill in the self cert. sheet (F1 - Appendix C Completion checklist and commissioning sheet) he looked at me as if I was talking Klingon!

MVHR Design v0.11 Google Sheet as XLS.xlsx

[Triassic]

On 05/12/2022 at 16:10, Gone West said:

I did it twice, once for SAP and then the real settings for PH, which is what we kept. The BCO wasn't interested in the SAP results, so for me it was a waste of time.

Interestingly our BC wasn’t interested in our results either. It was a tick box exercise. Thankfully he didn’t look at the results too closely as they didn’t add up. I only spotted the error after the event.