Ducting - are they all the same?

[gc100]

Hi,

 

I'm trying to source my ducting however I need a combination of round semi-ridged and ridged rectangular ducting (225x25mm) due to constraints of the house.

 

Firstly is all PVC antibacterial? I see some ducting claiming this property but others make no mention. With the rectangular ducting I never see this sort of claim. Anyone know if there is a special treatment I need to look out for or can I use any rectangular ducting?

 

Is there really any difference between these 2:

https://www.bpcventilation.com/white-90mm-ducting

https://www.bpcventilation.com/blauberg-radial-duct

 

Regarding bends - I presume I need to keep the number down as much as possible and keep the radius as large as possible?

 

Also it seems that the 45 degree bends are straight edged rather than curved (when looking at the 90 degree bends). Do you think these will mess the airflow more? I was thinking to use 45 degree bends rather than 90 degree bends to help reduce resistance, but I wonder if this would negate that.

 

  vs  

 

 

Thanks!

 

 

 

 

 

Edited May 26, 2020 by gc100

[Alexphd1]

On the blaubergs own website, there is two options of a standard pipe and a anti bacterial coating pipe at a extra cost. I dont know exactly what the coating is.

[MJNewton]

I've used both the red Airflow Airflex Pro and green Blauberg semi-rigid ducting and whilst they were nominally the same in terms of size and interchangeability the former was more flexible and felt like a better quality product.

[Gone West]

11 hours ago, gc100 said:

Firstly is all PVC antibacterial? I see some ducting claiming this property but others make no mention.

When I was considering a ground coupled heat exchanger all the ducting was anti-bacterial and the coating was a form of silver.

[Savage87]

PVC ducts are most likely not antistatic and possibly antibacterial

The radial ducts I think are made from a different material.

 

@PeterStarck is on the right track, the ducts have silver ion coating applied that make them antibaterial apparently.

 

I have 2 types of radial ducting in my house, both say the are anti-bacterial. You can't see any kind of coating on them.

Your first link is for a 90mm diameter duct and the second is for 75mm diameter, that is one difference. One is antibacterial and antistatic and the other isn't.

I have used 75mm green blauberg semi rigid duct which is antistatic and antibacterial. The thing that made me decide between the antibacterial and the standard one was that you put it in once and it can't easily be replaced. If I could, I would have gone for metal over plastic, but it wasn't possible in my retrofit project.

 

When it comes to the bends, it's always best to use 2x 45 degrees instead of 1x 90 degree. But looking at your comparison, I don't think it will be much differente. Depending on how much space you have for those flat channel bends, use the 2x 45s and if you don't have enough space use one 90 degree. Flat channel ducts have more resistence compared with round ducts.

[gc100]

Thanks all. Where are you sourcing them from? It seems the markup is massive on these items. It appears a lot come from this manufactuer - only 15 EURO for 50m of antibaterial!!! Obviously you need to buy in bulk though. Anyhow I digress:

 

So far I've found:

• https://www.bpcventilation.com/
• cvcdirect
• https://www.i-sells.co.uk/
• https://www.phstore.co.uk/
• https://www.paulheatrecovery.co.uk/

I'm struggling to find the perfect distribution box for me needs at the moment. 

Edited May 27, 2020 by gc100

[Alexphd1]

Best I found was £90 plus vat for 75mm with anti bacterial coating 50m roll.

[gc100]

Just now, Alexphd1 said:

Best I found was £90 plus vat for 75mm with anti bacterial coating 50m roll.

Where?

[Savage87]

how does a perfect distribution box look like?

 

Try looking on facebook market place or ebay for some bargains.

[Olf]

There seems to be over 30% premium for - well, 'Premium' - ducting https://www.bpcventilation.com/quietvent-radial-pipe-75mm-x-50m over standard https://www.bpcventilation.com/basic-radial-duct 

Probably for the piece of mind I'll go with antibacterial etc for supply, but do all the perks matetr for extract ducts, if I'll never breathe the air carried by those.

Or is it actually the opposite, because they suck out all the bad stuff from a house, they're more likely to be at risk of fungal/bacterial/dust growth inside them, with risk of making its way back to the rooms?

Edited October 11, 2020 by Olf