TOPIC: My expierience so far to become a Certified Energy rater.

Hey Dave

if I can help you with the building science aspect please feel free to call me and for me the unfortunate part of this whole thing is I believe as they do in Canada that the use of a blower door is incorrect as de pressurizing  a building is contrary to how the building actually behaves, each building  has a pressure plain that changes  as the day goes on, I just did a scan on a home circa 1830 and was amazed at the air loss I believe if this place was depressurized the flow would have been less and air loss not so visiable 

I agree with Mr. D. (not to create a rhyme...)

My understanding is that a blower door fan simulates winds of 80-90 mph.  For that reason it isn't considered a valuable test.  The house would have to be on top of Mt. Everest or something.  The negative pressure that Dennis refers to is not as useful as an IR image, for example, taken from the outside when the house is pressurized from the inside during HVAC use.  It is contrary as he says.

Dennis - what do you mean that the pressure plane changes during the day?  With the changing sun exposure of the building or temperatures or what?  Teach me, teach me...

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when air escapes from a building air pressure differentials between the inside of the building and the outside of the building are created (exfiltration) the result of this is air being pulled into the house to replace the air that has left (infiltration) the air maybe drawn out by a powered source ventilator,clothes dryer etc but also by the natural tendency of warm air to rise.sometimes between the point where air leaves at the top and enters at the bottom is a level where there is no air flow between indoor and outdoor air this is the neutral pressure plane,example if all air leaks were uniform through the whole building the npp would be about half way up the wall,but since all buildings do not leak in a uniform manner the npp is often found a few inches from the ceiling showing that most building have leaky ceiling areas so there is pressure driven transport diffusion driven transport , but the point remains the building has air pressure in different places during the day air is always traveling IMO

I disagree.

A blower door test is done at 50 pascals(Equal to a simulates 20 Mph wind at the exterior) The test can be done in a pressurazitation or depressurazition mode. The blower door and duct blaster are needed to do a proper audit. It is up to the rater to know how to deal with differant conditions and how to adjust the blower door. Having high winds blowing while doing a test is not going to work.

I do not know enough about the information yet, but I am trying.

Yes I need help with building science, but I have the material just need to focus. I am starting to understand - and + pressure/stack effect. Need to learn more about relative humidity/dew point.

Hey Dave

then we shall agree to disagree 

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when air escapes from a building air pressure differentials between the inside of the building and the outside of the building are created (exfiltration) the result of this is air being pulled into the house to replace the air that has left (infiltration) the air maybe drawn out by a powered source ventilator,clothes dryer etc but also by the natural tendency of warm air to rise.sometimes between the point where air leaves at the top and enters at the bottom is a level where there is no air flow between indoor and outdoor air this is the neutral pressure plane,example if all air leaks were uniform through the whole building the npp would be about half way up the wall,but since all buildings do not leak in a uniform manner the npp is often found a few inches from the ceiling showing that most building have leaky ceiling areas so there is pressure driven transport diffusion driven transport , but the point remains the building has air pressure in different places during the day air is always traveling IMO

Yes and it is up to the rater to determine were the neutral boundry is. And it changes.

Hey I am a novice here, but a month ago I knew nothing.

What is it that Srgt. Schultz said. " I know nothing and that is why I am here"