PassivHaus Refurb

[Andy Simmonds]

As some may know AECB has been advising the TSB on its retrofit for the Future Competition. Some of the presentations AECB gave are here, and this link is direct to the presentation I did on our refurbishment project. The powerpoint slides are accompanied by audio commentary of the speakers. http://retrofitforthefuture.ning.com/video/andy-simmonds-case-study-in

My presentation is missing a slide which may be useful, here is the missing slide.

[Rob Rickey]

We have just found our house and I want to achieve the best performance possible. I am new to AECB and Passivhaus, but I will get the PHPP soon. Setting the target is important, so can you recap the current best practice thinking for refurb? We will be adding a first floor studio to the garage as well, which could be Carbonlite Gold as it will be mostly new build.

[Andy Simmonds]

See http://www.aecb.net/forum/index.php?topic=2134.0 (I HAVE CORRECTED THIS LINK)
re observations on Mechanical Ventilation and Heat Recovery (MVHR) relevant to this thread.
By the way (BTW) MVHR is now to be called Heat Recovery Ventilation (HRV) or as my children call it 'The Wind Machine' (TWM) - in order to lose the 'MECHANICAL'/'IRON LUNG' connotations that get some people so over excited....

[Andy Simmonds]

interview with Soeren Peper regarding following queries:

'Widespread concern in UK about health problems of poorly maintained MVHR
and tenant ability to understand/operate them.  Can you help with any studies
in Germany or elsewhere?  This is becoming a policy issue at the highest
level. It is vital we make "Comfort ventilation" a positive thing in the
UK.'


He said that this issue was heavily researched about ten, fifteen years
ago, and you will find a huge variety of - German - literature on this topic, by
Wolfgang Feist (still working at the IWU Institut Wohnen und Umwelt -
institute for living and environment) and Witta Ebel, as well as architect
Schulze Darup and Uwe Muenzenberg from AnBUS (Analyse und Bewertung von
UmweltSchadstoffen - Analysis and evaluation of pollutants).

These being the main documents:
- Wolfgang Feist, IWU 1994 Air quality in Passive Houses 'Luftqualitaet im
Passivhaus'
- CD by Schulze Darup ISBN 3-9808428-1-9
- Conference proceedings, 7th Passive House conference in Hamburg, page
191: Article from Uwe Muenzenberg: indoor air quality in Passive Houses
'Raumluftqualitaet in Passivhaeusern'.
- Passive House Institute: Protokollband Number 8 'Materialwahl, Oekologie
und Raumlufthygiene', 1997 = Volume 8 of Research group cost-efficient
Passive Houses: choice of materials, ecology and indoor air
quality/hygiene.

Key is that filters are regularly replaced. In the first Passive House,
this was done, and the ventilation ducts were examined after several
years: no dust, no mould, no humidity insided the ducts.
If there are concerns that users would not change the filters themselves,
then there should be a maintenance contract between the house owner and an
external company to ensure that the filters are changed on a regular
basis.
During construction, a proper site supervision is crucial so that the
ducts are clean at the time they are installed.

[Chris Herring]

And in discussion with Wolfgang Feist at the AECB conference this year, he said that the ducts are still very clean now 18 years on.

[Nick Grant]

Andy, what are we allowed to call MEV these days?

[David OLIVIER]

Is this renaming part of the UK tendency to re-shuffle the chairs or reorganise the company/govt. dept. and feel one is accomplishing something?!

The whole topic was studied in detail by the R-2000 Program in Canada which found that airtight houses with MVHR were healthier in some respects than conventional houses. Actually I awlays refer to them being draughtproof as that is a more attractive concept.

I can't really see much better acronyms than MVHR and MEV. Comfort ventilation sounds rather bland and wind machine might be misunderstood.

I hope the TSB projects will include a number with MEV, not just MVHR. On my calculations, MVHR appears to be a waste of money unless buildings can be made as tight as Andy's house, since MEV neutralises the background air infiltration throiugh cracks and gaps, whereas MVHR doesn't.

D.

[Nick Grant]

David

Your MEV v MVHR analysis was excellent and made me think re our own house should I ever get around to fine tuning.

Nick

[Dave Howorth]

Personally I think there are [at least] three problems with MVHR as an acronym:

(1)  I can never remember which way round the the V and H go; I always have to say the words in my head as I type it

(2)  If you go to google scholar and search for 'mechanical ventilation', all the hits are concerned with patients in intensive care. If you add 'house', it's all about patients who are in intensive care but have been taken home. In other words, it already means something different and it has negative connotations.

(3) It's a FLEA not a TLA ( a four-letter-extended-abbreviation rather than a three-letter-abbreviation ) and people like TLAs. The American HRV is more snappy

On a more serious topic, is there any HR when you do MEV? Is there a good review of the energy balance somewhere?

[Alan Clarke]

I hope the TSB projects will include a number with MEV, not just MVHR. On my calculations, MVHR appears to be a waste of money unless buildings can be made as tight as Andy's house, since MEV neutralises the background air infiltration throiugh cracks and gaps, whereas MVHR doesn't.

D.

Unfortunately with the TSB measures being rated for cost effectiveness in SAP, MEV won't feature as SAP assumes that MEV performs the same as natural ventilation but with additional electrical consumption.

Alan

[Andy Simmonds]

I have uploaded in the file' section a pdf showing Relative humidity levels and temperatures and gas consumption for the period nov 09 - end jan 2010.
see database entry at http://www.aecb.net/cbpd/viewProject.php?id=7#downloads

We are working on a lovely new 'front end' for the database and also will be using it to show the TSB Retrofit projects in the near future in conjunction TSB. Hence it will be come a fully searchable and good looking combined database for refurbished and new build low energy buildings.