[Greenbuilding] Aggressively Passive: Building Homes to thePassiveHouse Standard

[John Straube]

Yes that is pretty firm. 

Sent from my BlackBerry®

-----Original Message-----
From: "George J. Nesbitt" <george at houseisasystem.com>
Date: Tue, 11 Jan 2011 12:40:49 
To: jfstraube<jfstraube at gmail.com>
Reply-To: george at houseisasystem.com
Cc: Green Building<greenbuilding at lists.bioenergylists.org>
Subject: Re: [Greenbuilding] Aggressively Passive: Building Homes to	thePassive
 House Standard

And rumor is you and Joe will be in Stockton in June:-)

On 1/11/2011 12:22 PM, jfstraube wrote:
> Hi George.  Thanks for your comments!  Appreciate the chance to 
> stretch my brain with this conversation.  Not sure, but I think I will 
> be in the Bay area doing a PG&E thing in April.
> You say:
>>> 1. 120 kWh/m2/yr of source energy
>> This is for your all of your energy at your building site. And using 
>> the U.S. DOE average for source energy conversions need to be entered 
>> replacing the E.U. #'s. And the appropriate #'s for Canada should 
>> also be used.
> Where is this documented?  The PHPP spreadsheet and handbook I 
> purchased from the Katrin's PHIUS show 2.7 and I cant find PHIUS 
> documenting anything else.  Are you told these things as part of the 
> secret initiation rites?
> I use values of 3.365 for electric, 1.092 for gas and 1.0 for PV as US 
> average values based on the extensive research work by NREL"
> "*Source Energy and Emission Factors for Energy Use in Buildings*
> www.*nrel*.gov/docs/fy07osti/38617.pdf
>>> 2. 15 kWh/m2/yr of annual space heating demand
>> and 15 kWh/m2/yr for space cooling, this and heating are based on 
>> site energy use (as opposed to source energy)
> I am pretty sure the value is demand, not consumption.  Energy demand 
> is always site energy by definition since it is demand, energy 
> consumption can be site or source and vary all over the place.
> So a better line might have been
> 2. 15 kWh/m2/yr of space heating and 15 or cooling energy demand.
> I am not clear if this means I can use 30 for space conditioning, or 
> that the cooling should be part of the 15 budget.
>
> The pressure test is a lot like the ASTM E779 because it was written 
> directly from this standard, and in fact the ASTM standard is a direct 
> copy from CGSB 149.1, the original Canadian standard.  Like a game of 
> telephone, a few things changed but nothing meaningful.
> The requirement of 1 Pa is a bit of a joke, as it is rare to find 
> anyone who can actually accurately measure 1 Pa.  The number must have 
> been chosen because it is a round number, as like most PH 
> recommendations I can find no science to support it.  While Feist is 
> much more flexible and reasonable than regional PH bodies, I am 
> surprised to to hear that he says this is a requirement: it is not in 
> the list of requirements in the documents. Katrin insists that an 80% 
> HRV is required (which could save a lot of energy relative to supply 
> or exhaust).  To get the same air quality with a supply or exhaust 
> only system you need to use more airflow.  That is a scientifically 
> proven as well as common sense fact. And/or you need to circulate the 
> air through the home more regularly.  But I digress.
> The changing requirements and recommendations and lack of 
> documentation of what is what is maddening to me. The claim is that PH 
> is rigorous, but following the online forums and looking at this 
> myself, it is remarkable imprecise and open to "Fesit told me I should 
> do this" and "Klingenberg say I must have this", etc. Which is not the 
> sign of a mature program.
>
>>> You have to meet 120 kWh/m2/yr site energy regardless of PV.
>> Correct, end of sentence
> The PHPP handbook and spreadsheet both allow PV to be entered and 
> account for it as 0.7.  I can provide the tab and cell number if you 
> cant find this reference.
> The energy thus generated is simply not allow to reduce the 120 number 
> for reasons that numerous online chat groups to to divine, because 
> there is apparently no official and certainly no scientific reasoning 
> behind it.
>
>> You have achieved an equivalent level of performance, an energy 
>> efficient house, and that's is what we all should be trying to 
>> achieve, no mater what we call it!
> This is the root of my concerns.  Here are some of the high level 
> approaches I would take:
> Seems to me, the number that matters is source energy per person, not 
> per square meter.  The heating restriction is simply illogical, as it 
> does not matter what it is (from the environments point of view) if 
> the source number is maintained.
> The problem with per person measures is that we dont know the number 
> of people.  Most codes use bedrooms + 1 as the number of people.
> In Denmark they have moved towards using a formula of the sort:
> X kWh + Y kWh/m2.
> Which rewards small houses, and penalized large houses if X is large 
> enough and Y small enough.  Energy Star version 3 will simply penalize 
> people for every square foot over 2200 (the average)
> Various countries have different laws for how to measure TFA: the 
> values of X and Y should be modified to result in the same target 
> between countries, reflecting existing real estate and tax law methods 
> of measuring TFA (Canada and US are the same, Germany is unique).
> In Sweden, such an approach was suggested, with two different sets of 
> values, one for the colder part of the country (like our Zone 7) and 
> one for the warmer (like our Zone 5/6).
>
> Until PV reaches around 20% of total annual market supply (decades or 
> further in the future and a happy time), the factor for PV should 
> scientifically be 1.0 or 0.97 (to account for some losses).  The value 
> for wood or biomass on site, should be zero, and the value for biomass 
> from off site should be some non-zero value (the 0.2 value in PHPP 
> seems as good as any guess).
>
>
> John Straube
> www.BuildingScience.com <http://www.BuildingScience.com>
>
>
>


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