Talk:Passive house

From Wikipedia, the free encyclopedia

	This article covers subjects of relevance to WikiProject Urban studies and planning, an attempt to build a comprehensive and detailed guide to Urban studies and planning on Wikipedia.
???	This article has not yet received a rating on the assessment scale.
???	This article has not yet received an importance rating on the assessment scale.

Information from Passive house (or a previous version of it) is being actively used in the pool of 'Did you know?' facts on the Energy Portal.

Contents 1 Catagories 2 Heat conductance 3 Natural ventilation 4 50Pa? 5 Sick building

[edit] Catagories

Susten.biz 03:12, 1 March 2006 (UTC) restored the categeries copy edited by User:Dogears

To me passive house methods are not a rigid group of visually simular buildings like log cabins or craftsman cottages. Rather they are an interdiciplinary package of concepts, techniques and approaches that pull in from many sources and reach back out into many styles and disiplines. Hence the wide range of catagories

((Category:Architecture]] This is certainly architecture

((Category:Building]] Passive houses are buildings as if energy use had consequences

((Category:Energy]] A kilowatt hour conserved is a kilowatt hour for some other use

((Category:Environmental design]] if a house that uses substantially less energy with improving comfort is not env design I do not know what is

((Category:Building engineering]] Defineately simulation is a foundation tool of design engineering and of creating passively heated houses

[edit] Heat conductance

Warning: I replaced "W/qm" with "W/m²" in the text – not sure whether that's correct. However, thermal conductance is measured in "W/m*K" (watts / (meter * kelvin)". We should somewhere add information on this odd "heat conductance" thingy used in this article (assuming it exists although it seems odd to omit the temperature difference). Rl 11:12, 11 May 2005 (UTC)

thanks W/qm*k is right - I did a mistake

[edit] Natural ventilation

The following section may well be correct, however it has been removed since it is liable to cause confusion - it is impossible to meet the Passivhaus heating requirements without mechanical heat recovery ventilation.

There is an emerging trend of building designers inspired by the Passivhaus concept designing for the most part to the Passivhaus specifications, but also taking an arguably more "passive" approach of using controlled natural ventilation rather than mechanical heat recovery ventilation systems[1]. This is some quarters considered to be the greener option, as mechanical ventilation systems require an electrical input-albeit in many cases a low input as low wattage motors come into use--to operate. Another perceived benefit is that natural ventilation systems include no moving parts, and may therefore be more durable.

Gralo 20:35, 13 February 2007 (UTC)

I'm not sure "impossible" is the word. Unpractical is more correct. The difficulty arises because in order to meet the low energy consumption guidelines the temperature difference between the outgoing and incoming air must be small, which means natural convection will be very slow. Thus in order to achieve the standards you would need to connect very many heat exchangers in parallel ( which is equivalent to use one with a huge cross sectional area ). 137.205.236.51 13:04, 31 March 2007 (UTC)

[edit] 50Pa?

50pa is about 100000Pa lower than atomospheric pressure. I'm gonna guess that was a typo in the article, but i have no idea what the actual standard is. Anyone who knows should probably fix it. Henry Corvel 21:11, 9 May 2007 (UTC)

50Pa is the pressure difference between the inside and outside; i.e. the building is tested at a pressure of 50Pa below local atmospheric pressure. I'll clarify the article. Gralo 14:19, 10 May 2007 (UTC), corrected 14 May 2007

I thought so, but i didn't want to change anything without proper knowledge of it. Thanks. Henry Corvel 19:07, 17 August 2007 (UTC)

[edit] Sick building

Wouldn't a building as well insulated as a Passivhaus be susceptible to sick building syndrome and the passing of microbes between inhabitants (important in the case of office buildings)? Shouldn't some mention be made of this? DirectorStratton 03:26, 14 May 2007 (UTC)

Passivhaus buildings involve a combination of inter-related and inter-dependent technologies and techniques and it is important that all are incorporated into the building. Provided this is done then sick building syndrome is unlikely. Certain aspects of the specification help to guard against this - for example the high levels of window insulation decrease the chances of mould forming as the surface temperatures are higher than in traditional buildings, and a carefully designed ventilation system maintains a regular (but carefully controlled) flow of fresh air, even with all the windows closed. Also, each building can be (and must be) proven using the specially developed and tested Passivhaus simulation software before being built. Gralo 14:04, 14 May 2007 (UTC)

Answers are already given in the sick building syndrome article: In most oft the sick building cases the reason was moisture and mold grow. There are a lot of different possible reasons for high moisture contend in building materials (like leaks in the roof, broken water pipes etc.). However, an important one is high air humidity due to (too) low ventilation rates. That is the main motivation why a sufficient ventilation system is required in a passive house. The minimum passive house ventilation requirement of 0.3 ach just meets the requirement of some 8 airchanges per day given in the recommondation. There have been, however, a couple of scientific publications on indoor air quality measurements in passive houses, always proving it has been very good. User: W. Feist, 2007-May-25