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Standards and labels: BBC or Passive House? Who says what?

published: 17/01/10, 13:15
by Christophe
Read in the last natural habitat: a house is considered passive when its TOTAL PRIMARY energy consumption is below 120 kWh EP / m².a it is a surprisingly high value I find ...


So I quickly checked our case:

- 4000 electric kWh (professional part included) = 10 320 kWh EP (supposing that in BE the coef is the same as in FR: 2.58).
- 2 to 3 Tons of wood = approximately 10 000 kWh EP.

Overall, reported on the surface we are (just) less than 120 kWh EP / m².an ! So if we replaced wood heating with halogens which have 90% thermal losses, we could pass our house (which if it is sufficiently well designed thermally is still very far from passivity even if our large solar surface must help ) as passive because we would be below 15 kWh "heating" ???

Is there an error in the 120 kWh EP / m².an number?

Because if it is to remove the heating and heat with halogen bulbs or an electric oven (double flow CMV allowing heat recovery from the oven throughout the house) ... I do not see the point ... in short there is a large "tolerance" between 15 final and 120 kWh EP / m² for the passivity standard!

But I'm glad we take into account GLOBAL electricity consumption!

So this subject would be welcome for take stock of the different energy standards Low Consumption Building or Passive House (HQE is rather focused on materials, even if a home HQE is often passive since the 2 approaches are strongly related) and especially the real efficiency of the BBC or passive houses ...

Edit: here is a document from comparative summary of 4 energy labels currently in force: RT2005, Effinergie, Passive House and Minergie

published: 17/01/10, 13:27
by Christophe
Good after a quick search, apparently the figure of 120 kWh EP is good because it is taken, for example, in this article of 2006 (already!):

Remember that these houses must consume only 15 kwh / m2 / year, it is far from the regulation RT2005 with its maximum of 85 kW / m² / year. In total, theprimary energy demand must remain below 120 kWh / m² / year, including heating, hot water production, lighting and home power consumption. This implies that the behavior of the occupants will have to be exemplary. In this regard, an awareness will be made on energy savings and the use of equipment with lower energy consumption.

What is “surprising” is that the number of inhabitants is not taken into account, now you will tell me: m² and number of inhabitants are linked ... but still ...

The BBC label would therefore be, a priori and paradoxically, more restrictive than "passive house" because it is still difficult to consume 120-65 = 55 kWh EP / m².year in an average house just in household appliances if? Yes? no? Objections?

published: 17/01/10, 14:58
by aerialcastor

Yes, except that to be "passivhauss" you need less than 120kWhep / m² / year in primary energy and less than 15kWh / m² / year in final energy and that is what is hard to achieve. I think the value in kWhep is high because the Germans turn to thermal.

like the little doc that summarizes well

published: 17/01/10, 15:31
by aerialcastor
I read a little fast .... next day Saturday night requires ImageI still have my head in the pie

You were already talking about 15kWh / m² / an in need of heating. So I confirm your numbers.
Otherwise the coefficients Ep / Ef are not the same, they are given in the doc above.

published: 17/01/10, 19:29
by Christophe
Ok for the coefficients, thank you for the doc, everything is summarized in 1 table, great that's what I was looking for: ... U2O8Sm.pdf


Could someone explain the disparity of the coefs?

a) 2.58 or 2.70 for electricity for passive houses is because we take the coef of Germany?!?

b) More surprising: from 0.2 to 1.0 for wood?!?

What I especially wanted to say is that in passive house the difference between 15 kWh Ef and 120 kWh Ep is important and that it is "easy" to shift heating needs to lighting needs to take advantage of their losses. heating ... I hope I'm clear it's also Sunday for me :D In short: it's a kind of cheating ...

I will make our assessment more accurately thanks to the table following the standards 4!

Image for the find!

published: 17/01/10, 23:01
by minguinhirigue
There is indeed a great disparity between the different European standards. By the way thank you for the table it is really nickel.

When analyzing the table, attention should be focused on:
- the primary energy coefficients, which vary enormously according to the valuation considered for biomass.
- the positions actually covered by the standards: the German standard is the only one to include any the appliance in the calculation of primary energy.

Knowing that a job such as drying clothes is a real mess as long as it is internal to housing. In one case he eats the latent heat of the house to evaporate the kilo of water present in each kilo of clothing, in the other, the resistance of the automatic dryer consumes the same thing!

Another point, all standards do not allow the depreciation of the energy bill by pico-production facilities:
- the passivhaus standard invites to consume less heating (15kWh max) before thinking of putting photovoltaic roof to dampen its overall bill.
- the BBC standard, it does not care whether the house is a "passive" house or if it is a thermal strainer which redeems an energy bill using photovoltaic panels!

FYI, there is a more restrictive standard, the minergie standard P Eco, which makes the balance of gray energy!

published: 20/01/10, 11:57
by Christophe
Good remarks even if I find the 120 kWH Ep high enough for a "passive" house (therefore supposed to have 0 heating) because it allows an offset of the household appliance on the heating ...

I have not yet had the time to make our assessment but it would be good if we are several (5 or 6) to do so to see where we are with respect to these standards! Maloche, are you there?

I will prepare a small OpenOffice file as soon as I find the time!

minguinhirigue wrote:FYI, there is a still more restrictive norm, the minergie P Eco standard, which makes the gray energy balance !

Wow can you tell us more? Is it possible to estimate on an existing construction?


published: 20/01/10, 12:25
by Did67

Indeed, remember that a standard is only a measuring instrument that allows labeling (eg that I know better: "organic" does not mean, as many believe, without pesticides; it only means: "without the use of synthetic pesticides" - therefore we use natural pesticides - even toxic ones: eg copper; and we "collect" pesticides from the neighbor - it is not illegal; it is true that as a general rule, there are less).

The passive house concept is "focused" on the issue of heating, but it is still top of the range, so a lot of equipment (VMC DF, computer TVs, MAL, freezes, etc ...) for "bobos" of owners (I am schematizing - I also think, if I rebuild, to be inspired by the "passive").

I also think that we must distinguish labeling (and "market value" that goes with it) from the use we make of it. In short, an electric vehicle that is used for nothing will remain a pollution! It is the same for a passive house in which we live like an energiegloutovore !!! (e.g. 4 TV screens on 24 hours a day)

published: 20/01/10, 12:35
by Did67
Christophe wrote:
a) 2.58 or 2.70 for electricity for passive houses is because we take the coef of Germany?!?

b) More surprising: from 0.2 to 1.0 for wood?!?

a) I believed that the efficiency of power plants, even nuclear, is around 30/35% + line losses. So I am not surprised. When you "burn" 1 kWh in your house, it is roughly 3 kWh E = mc² which were available at the plant (even nuclear - even if it is utopian to have a small reactor at home).

b) I see no other explanation than a "standard" which is based on the CO² released, therefore a "standard sensitive to global warming". Hence the 1,1 for fossil energies (with gray energies) ...

published: 20/01/10, 12:54
by Christophe
Power stations have roughly the same performance everywhere ... gas news exceeds 50% ...

The 2.58 ca makes an average yield of 38.8% of the Primary Energy to the consumer: it is therefore high but it also includes the REs including hydroelectricity (so 0.0 EP because I do not think that the gray energy is included in this coef.)

As the energy diversity is completely different in Germany, this is surely why the coef. (2.70) is a little worse ... they must still have quite a few "old" coal plants in operation? (from the Soviet era?)


In any case: no reason to take 2.7 as coef. if you are in France or why do you have to explain to me why?

The differences in the coefficients on the wood are much more intriguing ... : Shock: :?: