[Greenbuilding] ventilation standards

[Nick Pine]

johnsbone at gateshead.plus.com writes:

>> ...our National (England & Wales) Building (Code) Regulations (April 2006
>> onwards) sets as minimum air flow ventilation limit (and most of Europe)
>> at 10 litres per second (per fulltime occupant).
>
> ... 1 L/s is 2.12 cfm, if I did that right, so that's 21 cfm per fulltime
> occupant.
>
>> New building now have to be air tested for their air leakage rate. And 
>> the
>> limit for this is 10 M3 per M2 per Sec at 50Pa pressure.
>
> Per M^2 of floorspace or building envelope? Sounds like a lot...

Turns out it's m^3/HOUR/m^2 of floorspace, so 3 at 50 Pa would be
about 3/20 = 0.15 of  natural air leakage, eg 1000x0.15x200/3600
= 8.3 L/s (17.7 cfm) for a 200 m^2 house.

Nick