Annual conference 2009

[Chris Herring]

It would be great to get feedback and discussion on the conference here.  

[Nick Grant]

What a great conference, just never enough time to catch up with friends.

I heard that Dr Feist explained the physics of multifoil insulation in a workshop I couldn't go to. Would really appreciate someone posting on this as the magazines still seem to be full of adverts for the stuff.

multifoil discussion moved to http://www.aecb.net/forum/index.php?topic=1955.0

Nick

[Mark Siddall]

Hi Nick,
Like you I found the conference to be a great success and that I didn't manage to meaningfully catch up with all the people that I wanted to. Including you!

On the multifoil issue I was surprised to find that Dr Feist seemed to accept the concept, in terms of reduced radiant transmission. He also made particular comment that an air gap is required between each foil is required. In his view to deliver the required performance about 150mm (I think that's what he said) was more likely to deliver the required performance. I think that this is quite a lot more than some would have the building industry believe. Dr Feist focused upon the U-value at the center of the multifoil (the ideal zone), I did not manage to draw him on the fact that these foils are likely be crushed at centers, creating a thermal bridge (albeit a batten or a cavity tie).

Dr Feist also mentioned that air gaps within and between insulation needs to be avoided. With multifoils I question how suitable sealing may be achieved and how they can be successfully turned around corners. Finally I did not manage to report the findings from the BRE. These observe that in masonry construction mortar snots fall on the foils and reduce the ability to minimise radiant losses.

Rest of Multifoil discussion moved to http://www.aecb.net/forum/index.php?topic=1955.0

Hope this helps. (I'd be interested to hear other peoples recollections/thoughts.)

Mark

[Mark Siddall]

By the way, I think that the AECB Conference would be the ideal opportunity for the growing PHPP user group to meet and discuss the software (benefits, toggles, tweaks and wish lists, etc.) This could all be fed back to PHI to assist with development.

(An annual meeting is suggested by the CarbonLite programme, the conference would seem to be a good way of enabling this to happen.)

Mark

[Geoff Stow]

The verbal feedback on the conference has been very good and we will be sending out feedback forms very soon to help with planning next years event.

Wolfgang's was not the only mention multi foil one of the presenters had used a breathable version on a project. As soon as I remember which one it was I will follow it up.

Thanks to everyone who made the event such a pleasure.

Geoff

[Philip Jordan]

Thanks very much for the conference - my 1st in many years of membership:
happy to respond with feedback but meanwhile please where's the stuff on
Passivhaus as premiered during the conference - all 39 pages or whatever etc?

[Chris Herring]

Philip

I presume you mean the Passivhaus/Gold design guidance (more like 130 pages)?   Just awaiting webmaster posting...will be on Carbonlite website, hopefully in next few days.

[Paul Singleton]

Can anyone give any feedback on the workshop sessions held by Wolfgang Feist? I'd like to know what the conclusions were to these two questions:

Can we insulate too much?

Do we need triple glazing?

[Mark Siddall]

In brief:

Not unless you end up with about 1m thickness.

Debatable. Swings and roundabouts suggest that the answer is yes (if not then you need lower U-values thus incurring greater cost anyway).

Mark

[Paul Teather]

The French "Maison Passive" web site has produced a summary study looking at different climate zones, in France, of which there are 4 under their Building Regulations (Regulation Thermique).

They found that simple double glazing is possible in some zones.

I suspect that high quality double glazing (Uw = 1.2, so insulated Frames) may be OK in some circumstances in London (urban heat island), and possibly other locations in the UK. THis would require high standards elsewhere (particularly thermal bridging).

The barrier to advising further on this is the lack of Climate data for the UK - at the moment we only have Manchester.

Another aspect to consider - if we design to current Climate data that shows the need for triple glazing, where does this leave is if, say in 10 years time, the Climate has warmed up so that only double glazing is required. The marginal benefit of the extra spending will have only been in place for less than 10 years (Note: THE UK climate appears to have already warmed up by approx. 1C in recent decades)

[Nick Grant]

OK I couldn't do those 2 workshops but would flag up another reason for triple glazing which is surface temperature rather than just whole building heat loss. This has been covered elsewhere on the forum. In our house we get condensation on bottom edge of our DG units when around 0C outside. Also I assume triple glazing reduces thermal gains in summer (heat dumped at night via venting rather than through the glass).

Nick

[Mark Siddall]

Paul,
I've looked into this in great detail. South of Newcastle you can use double glazing to satisy the comfort requirements, however, the trade off is that the building fabric has to be improved to compensate for the additional losses (our climate is not sufficienctly forgiving). This means that the additional costs are simply relocated rather than mitigated. The best solution would be double on south triple elsewhere.

Regards,
Mark

P.S. We need PassivHaus standard frames for the double glazed option, it may be easier and cheaper to go tripple with a timber frame ~ Uw 1.0

[Paul Singleton]

Interesting that you need to get to about 1m thickness of insulation (presumably mineral wool or similar) before you get to the stage of having too much. Has anyone ever done this? I could imagine lofts could get to this thickness, but walls? I'm starting to think my 250mm fully filled cavity isn't very much now!

With regard to triple glazing I can see it would be an advantage in both winter and summer as, like other insulants it would slow down the heat transfer rate (heat out during winter, heat in during summer). If our aim is to achieve a pleasant stable environment in buildings then triple glazing must be a step in the right direction. But then again you could always open your DG windows in the summer if it gets too warm!

I don't want this thread to concentrate on just triple glazing so has anyone else got any questions or comments about the 2009 Annual Conference? I'm sure there's a lot of other people out there who would be interested in the topics discussed at the conference.

[Michael George]

In brief:

Not unless you end up with about 1m thickness.

Mark

Hi Mark. Are you able to justify this statement? Or did Dr Feist do so?

[Mark Siddall]

Dr. Fiest made the statement. The justification was embodied energy vs energy saved during its lifetime (saddly I didn't catch the life span but judging from some of his other work on this issue I'd say 80 years.) Since then, perpetual skeptic that I am, I've done some calcs of my own. If I get a moment I'll check the 1m thickness argument and get back to you. (Obviously depends upon insulation type, but the presentation was looking at EPS, you'd expect a greater thickness for cellulose.)

Mark