[Greenbuilding] Passive House, WAS why do houses have to have stay the same tempinside?

[Corwyn]

On 8/19/2012 7:28 AM, Gennaro Brooks-Church - Eco Brooklyn wrote:
> I love Passive House but the one big issue I have with it is that you
> are putting all your eggs in one basket. Once you do an air pressure
> test and try to find the leaks you realize how a simple tiny hole
> drastically changes the pressure of the building. Yet all the
> calculations - heating, insulation, cooling etc - are based on there
> not being any holes.

This is quite simply not true.  PH has a lower limit for amount of holes 
(ACH50 of 0.6).  If you want some leeway, you can reduce the leakage to 
below this number.  No house is without any holes.

> This means that some time in the future WHEN the
> building gets a hole (because it will) all of a sudden your heating
> and cooling systems are completely inadequate.

Sadly, most Passivhaus buildings are unable to find heating and cooling 
systems *small enough*.  So there is usually far more unneeded heating 
and cooling capacity than in a comparable leaky building.

> And good luck finding that hole.

You find it, the same way you found it during construction with a blower 
door.

Frankly, building a crappy house, *because* a well-built house might 
someday become a bit worse (and lose say 20% of the heat of the crappy 
house instead of 10%) is lunacy.


Thank You Kindly,

Corwyn


-- 
Topher Belknap
Green Fret Consulting
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