EPS insulated ducting

[dnb]

It's getting to the time of installing ducting for ventilation. I am planning on MVHR and cooling so I need to look at insulated ducting to avoid condensation. Does anyone have experience of EPS rigid insulated ducting such as is sold by Verplas, Titon or Kair?  It sounds a good idea on the face of it, but I'm a little concerned about making a rod for my own back when it comes to fire spread prevention. I also note that Kair seem to be discontinuing a large number of products, so again it might be something to be concerned about.  My thinking is that metal ducting is more work to insulate, heavy and expensive to ship to my location so avoiding it may well be benefitial to the bottom line, but if it gives a substantially better solution then that's the way it needs to be.

[Mr Punter]

You may find that single room split AC is the way forward for cooling.  It can sometimes be simpler not to combine different functions in a single system.

 

The nice thing about it is the pipework is very small bore and very well insulated.  I would not run cold ducting inside a warm house.

[Dan F]

We have supplementary heating/cooling via MVHR (first floor only) and have just used foil-backed mineral wool to wrap standard 90mm radial semi-rigid ducting.

 

The large duct that feeds the first-floor manifold (as well as out intake/exhaust ducting) uses this product which has worked well: https://www.ubbink.com/en-gb/ventilation/residential-ventilation/residential-ventilation/aerfoam-insulated-mass-flow-ductwork

Edited June 1, 2021 by Dan F

[Marvin]

On the MVHR whole house system here we used Domus Thermal Duct Insulation on rigid duct. probably more work fixing but less cost buying I think...

 

https://www.domusventilation.co.uk/ventilation-solutions/ducting-range

 

I used cable ties to keep the insulation on. 

 

 

[Thorfun]

On 01/06/2021 at 17:45, Dan F said:

We have supplementary heating/cooling via MVHR (first floor only) and have just used foil-backed mineral wool to wrap standard 90mm radial semi-rigid ducting.

 

The large duct that feeds the first-floor manifold (as well as out intake/exhaust ducting) uses this product which has worked well: https://www.ubbink.com/en-gb/ventilation/residential-ventilation/residential-ventilation/aerfoam-insulated-mass-flow-ductwork

hey @Dan F. how are you finding the supplementary cooling via your MVHR system in this hot weather? is it doing the job? just about takes the edge off? or not very satisfying at all?

 

I'm considering supplementary cooling and our M&E guys have suggested using Split AC rather than using the MVHR system. just wanted your opinion of it please.

[Dan F]

8 minutes ago, Thorfun said:

hey @Dan F. how are you finding the supplementary cooling via your MVHR system in this hot weather? is it doing the job? just about takes the edge off? or not very satisfying at all?

 

I'm considering supplementary cooling and our M&E guys have suggested using Split AC rather than using the MVHR system. just wanted your opinion of it please.

 

We're not in yet ? .   Are you using ASHP, if you are would you not look at using fancoils rather then indpendant AC units?  Seems a shame to use split A/C on a new build.

 

The MVHR approach will only work well if your cooling demand is already low, and it's just to ensure bedrooms aren't few degress warmer.  I can't remember, fif you have any cooling demand numbers to see how effective this would/wouldn't be?

 

[Thorfun]

4 minutes ago, Dan F said:

 

We're not in yet ? .   Are you using ASHP, if you are would you not look at using fancoils rather then indpendant AC units?  Seems a shame to use split A/C on a new build.

 

The MVHR approach will only work well if your cooling demand is already low, and it's just to ensure bedrooms aren't few degress warmer.  I can't remember, fif you have any cooling demand numbers to see how effective this would/wouldn't be?

 

I have no cooling demand numbers sadly but I do have a very low overheating risk as we have external blinds. I'm looking for something as a just in case kind of thing. I was thinking of fan coils run off the ASHP but involves more ducting through the house whereas the pipework for a multi-split AC system is small. but, the flip side is the wall units for the split AC are large and the fan coil ducting opening is unobtrusive as far as I know.

 

I will mention the fan coils to the M&E company. 

 

But I was also thinking that the split AC could be used as supplementary heating in the bedrooms if required and would negate the need to run UFH pipes.

 

ps. hope you're in soon! was back in March that you were plastering iirc so you can't be too far away.

Edited July 22, 2021 by Thorfun

[Dan F]

We have fairly large overhangs, high levels of insulation and airtightness and external blinds on most windows which will be automated by Loxone.  So our calculations might give you a good idea:

 

Cooling Load:                                     335W

Cooling Load (no blinds):                1.3kW

 

Cooling Output UFH (GF Only):       3.6kW.      (UFH circuit @ 17C)

Cooling Output MVHR (FF Only):    1.1kW.     

 

I think that 1.1kW may be based on the same 17C though, as the Comfopost datasheet suggests a cooling output of 2.1kW for 190m3/h with flow temp from ASHP of 7C.

 

Given these numbers, MVHR cooling for us was a no brainer and fancoil/AC was clearly not required.

 

[Mr Punter]

2 hours ago, Thorfun said:

But I was also thinking that the split AC could be used as supplementary heating in the bedrooms if required

 

It will be so rare that you need any heating in bedrooms if they are upstairs.  The heat from our towel rads more than heats the upper floors and our place is fairly standard insulation and airtightness.  The cooling could be useful on the odd days when it is really hot and it means you don't need to have the external blinds down all the time and be in the dark on a nice sunny day.

[Thorfun]

1 minute ago, Mr Punter said:

It will be so rare that you need any heating in bedrooms if they are upstairs. 

I hear and read that often on here and it's not that I don't believe the people who say it, it's more that it's hard to get my head around the concept of not needing heating! I guess it's a leap of faith (although I'm sure science could well be involved in doing the calculations try telling my brain that) but the voice in the back of my mind keeps saying 'what if it isn't?' and then maniacally laughs at me.

[Dan F]

1 hour ago, Thorfun said:

I hear and read that often on here and it's not that I don't believe the people who say it, it's more that it's hard to get my head around the concept of not needing heating! I guess it's a leap of faith (although I'm sure science could well be involved in doing the calculations try telling my brain that) but the voice in the back of my mind keeps saying 'what if it isn't?' and then maniacally laughs at me.

 

Give @joth's post on bedroom overheating in spring a read.. then you might change you mind ?

 

Some people do report bedrooms being 19C vs. 21C in the winter.  We don't think this will be a concern for us, but the Comopost will allow us to add a very small amount of supplementry heating if it's ever required.

 

Edited July 22, 2021 by Dan F

[Dave Jones]

could you not build a box at the instake part of your MVHR and stick the air con head inside it so cool down the incoming air ?

[Dan F]

44 minutes ago, Dave Jones said:

could you not build a box at the instake part of your MVHR and stick the air con head inside it so cool down the incoming air ?

That's what the ComfoPost I refer to is.  But rather than an air-con it uses cold water from your ASHP. https://www.zehnder.co.uk/comfopost-range