DIY MVHR

[joe90]

1 hour ago, ProDave said:

75 metres does sound not very much. and I didn't think my house was very big.

 

Yes I was supprised but clever planning ? And central location lends itself to economy of all pipework including plumbing. Can I mix Domus and quiet vent?, the pipework looks the same?

[PeterW]

43 minutes ago, joe90 said:

 

Yes I was supprised but clever planning ? And central location lends itself to economy of all pipework including plumbing. Can I mix Domus and quiet vent?, the pipework looks the same?

 

Think so... and I may need 15m extra so that 25m over is becoming sought after !!

[ProDave]

At the risk of teaching how to suck eggs. You are allowing two runs per vent aren't you?

 

I should be starting my ducting soon, so I'll let you know if I have ran out.....

[PeterW]

9 minutes ago, ProDave said:

 

At the risk of teaching how to suck eggs. You are allowing two runs per vent aren't you?

 

 

I thought you only needed to do that for high volume extracts or intakes ..?

[ProDave]

1 hour ago, PeterW said:

 

I thought you only needed to do that for high volume extracts or intakes ..?

That's what my designer specified for mine, and thought that was what everyone was doing?

[jamiehamy]

1 hour ago, ProDave said:

That's what my designer specified for mine, and thought that was what everyone was doing?

BPC specified on our design which are single and which are double ducted vents. 

[CC45]

The longer runs on ours are doubled - these go to the three largest rooms so I guess extract volumes and air noise in pipes comes into play.

[jack]

I believe doubling up is only needed (if it's needed at all) where the run is particularly long and/or the room has high extract rates.  The only double on our house is one of the two kitchen extracts. 

 

 

[ProDave]

Interesting about doubling up.  Most of our runs are long due the to mvhr being off to one side in a plant room above the garage. At building warrant time my designer got a quote from a different supplier (not BPC) and they designed a very similar system based on the same size radial ducting, and specified two pipes for each run, so that is what I am sticking with.  The only short runs are the utility and en-suite and as these are high flow rooms I guess they need two pipes anyway.

[jack]

The double kitchen run is about 9m, from memory. There are a couple of others (bedroom supply) that are around 10-12m, and they're single duct.

 

From memory, my ducting has a slightly larger cross-sectional area than the stuff most on here are using. That might explain the relatively low number of double runs in my layout.

[ProDave]

@joe90

 

My pallet full of big red duct arrived today.  If you have not placed your order yet, you might want to wait until after the weekend.  My plan is to try and lay all the duct in this weekend so I will then know if I have any left over, or am a bit short.

[Jeremy Harris]

I found that the calcs showed that our kitchen run (similar length to @jack 's) needed to be doubled up, but all the others were well inside the capacity for a single run.  When I came to balance the system I found that the kitchen run had to be throttled right back, so that would have been fine on a single run, too.

Edited June 2, 2017 by JSHarris

[ProDave]

@joe90

 

I have laid in all my mvhr duct today.  I have 13 metres of duct left over, so I doubt that is enough to prevent you having to buy another roll is it?

 

If you don't want it then in due course it will go on the for sale forum.

[joe90]

Sorry for not replying but I have been away on site and have no broadband. I have now come to the pub to use their broadband ( honest?)

 

As above with .Jeremy's comment I am not doubling up and my build is similar to his in size etc. Yes Dave I may be interested but yet to order or measure accurately.

 

as per my earlier question is their any difference between the Domus pipe ( blue) which is sold in 25 MTR rolls) and quietvent ( red) .

 

i am making my own plenum s with 90' bends and room vents from EBay ( saved about £150) and making my own silencers and manifolds from  MDF. 

[PeterW]

13 minutes ago, joe90 said:

 

 

i am making my own plenum s with 90' bends and room vents from EBay ( saved about £150) 

 

Got any links or pictures..??

[joe90]

Just read the other thread on MVHR and cooker hoods, sorry for using the word plenum ( but the "terminal" from BPC does connect two pipes into a larger outlet pipe!!!!!). Peter, not done it yet but I got the bits from fans 4 lesson EBay, I will post a picture when I have got some flexible pipe ( quietvent or Domus ??????).

[joe90]

Does anybody know the difference between Domus semi rigid duct and quietvent or are they interchangeable please?

[PeterW]

On 22/06/2017 at 11:53, joe90 said:

Does anybody know the difference between Domus semi rigid duct and quietvent or are they interchangeable please?

 

Same spec aren't they..?? As long as the dimensions match I wouldn't worry. 

[Jeremy Harris]

My understanding is that the design rights for 68mm bore, 75mm OD, semi-rigid duct have been sold to at least three companies, who sell the same duct.  The ones I know of are HB+, Domus and Quiet Vent, but there may well be others.

[joe90]

Sorry it's been so long but I have been on site for three weeks and have no broadband there yet. Here is a picture of my Heath Robinson room plenum, saved me about £20 each, and I need 9. I have started mounting the unit and will next show pics of the homemade manifold/silencer arrangement. 

 

Question,

I have 5 supplies to rooms and 4 extracts and I was wondering  that because I have a warm roof and heat rises is it worth putting another extract up to  the ridge of the loft to recover any heat that finds its way to the highest point in the house ??.

 

 

Edited July 7, 2017 by joe90

[ProDave]

I had the same, 5 supply points and 4 extracts, so I added an extract point from the plant room, thinking with the buffer tank in there it might get a bit warm.

[joe90]

Well here is the homemade manifold/silencer, yet to fix in place but will update when I do. Notice the sound absorbing foam baffle, I recon less sound will transfer it has to go around corners !!!!!

[Barney12]

On 07/07/2017 at 16:14, joe90 said:

Sorry it's been so long but I have been on site for three weeks and have no broadband there yet. Here is a picture of my Heath Robinson room plenum, saved me about £20 each, and I need 9. I have started mounting the unit and will next show pics of the homemade manifold/silencer arrangement. 

 

Question,

I have 5 supplies to rooms and 4 extracts and I was wondering  that because I have a warm roof and heat rises is it worth putting another extract up to  the ridge of the loft to recover any heat that finds its way to the highest point in the house ??.

 

 

 

Out of interest. How will you join your flexible duct lengths? Or are you going to bond each one in at the end?

[joe90]

Hi Barney, as per the picture I used pieces of foam to keep the pipe in the middle of the socket and bonded with expanding sticky foam , at the manifold it's a cable tie to hold it still and foaming glue to seal. Hopefully it will never need taking apart but if it does the one in the picture was simply cut apart with a Stanley blade and re fixed to the in situ pipe again. Heath Robinson it may be but it works ( and is a lot cheaper). More pics to follow ( when I am allowed up the pub again?).

[joe90]

Well it's nearly all in ( pics to follow) one problem I have yet to deal with is how to control airflow per room from the manifold (I don't want to adjust airflow at the rooms), I think I read about knockout rings in proprietary manifolds but mine is DIY, ed. I could use the end caps from the flexi pipe and cut holes in them but don't have enough, has  anyone got quiet vent pipe ends that come on the roll to stop muck getting into the pipe?????, I will pay for postage.