Blower Door Leakage Reveal for Chaz's DIY Home Build (ERV, Dehu, Reverse Soffit in Vented Attic) 

I will be great to see Chaz's next set of numbers. I hope he hits a number that lights up his day!

The number i have seen is 5ach50, which is equivalent to the required ventilation. Hence, it is the point where balanced ventilation is worth doing. But i don't know what climate that's in, as natural ventilation is climate dependent

There is not really a set number. This is because the design of the house, design of mechanicals, location of construction flaws, climate, weather, and sun exposure (and likely a few other things I'm leaving out) all contribute greatly to the natural air flow in a house. For example lets take two houses both are Identical and perfectly air tight except for the placement of two equally sized holes in each. On a warm overcast night (requiring A/C) with no wind If house #1 has its holes both on the top and house #2 has one hole on its top and one on its bottom then house #2 will have an almost infinitely higher air change rate in the house, because the higher density conditioned air will "fall out" of the bottom hole and draw in warm air in the top hole, where as house #1's air will mostly stay in place because house #1's air is mostly more dense than the higher temperature outdoor air at its top where its holes are. Yes, this is a ridiculous example. But it's set up that way to illustrate the point. In reality there is no "right amount" of air changes, the purpose of ventilation is to reduce indoor air pollution and/or adjust gas concentrations. The absolute low end of ventilation should probably be around 4 CFM/person, however this will likely not take care of the pollution sources in the house, and will lead to periods of increased CO2 while the person is exercising. Passive house requirements for ventilation along with point source (ie oven, stove and bathroom) ventilation are a pretty decent place to be though. Those requirements are basically 15 CFM/person and the ability to go up to 0.3 air changes per hour. The reality is that every home no matter how air tight really should have mechanical ventilation.

Fingers crossed buddy- FYI the HVAC installer saw this vid and called Chaz right away, said he knew exactly what the dehu leakage was and he’d be there the next day!

@@HomePerformance kudos to them 👏

He's not, but he's in the building industry so has a lot of contractor friends he can wrangle when he needs to. Like you buddy.

About half of the ductwork is in the vented attic. That's the difficult part.

Yes, the shower is the "best" place. However other placements may have other benefits worth considering ie: behind and lower than the toilet seat can really help with "other" smells.

Do both if the in-shower extract won’t also grab the toilet odors

Correct- it was actually 8 Pascals when I measured it the first time. The magic of cinema.