Suplly Air Diffusion - ADPI

[remp]

Got supply air diffusers for an internal zone of an office supplying 2.5l/s/m2 of air for air conditioning needs. I know it sounds a little low for air diffusion purposes and the consultant is complaining because he is used to the so called industry standard of minimum of 4.5 l/s/m2. He wants me to prove that I will get propper coverage with the diffusers and he wants me to do an ADPI calculation. Does anybody know how to do it easily??
By the way I have linear slot diffusers - which the manufacture guarantees excellent diffusion pattern, we are currently getting them tested in a lab.

Regards

Billyq

 

[ad77]

ASHRAE Fundementals Space Air Diffussion gives a run down of ADPI.

It provides a simple table with various air diffusion types, diffusser spacing, room load and maximum ADPI achievable.

Are you from Melbourne Australia?

 

[remp]

Anthony,

Sydney... and tis bloody hot mate!

What do you think of that 4.5L/s/m2 rule of thumb that every body sticks to?

Regards

 

[ad77]

the 4.5 l/s/m2 (6 ac/hr for a 2.7m high ceiling) goes back to commonwealth government office accomodation design brief and appears to have become a default minimum airflow for internal zones. Also, many hospital design briefs call up 6 ac/hr as the minimum.

i believe the 4.5 l/s/m2 as being slightly high as it typically in excess of the room sensible heat load. your proposed 2.5 l/s/m2 appears low (only based on gut feel).

so, using the Air Diffussion Performace Index and being somewhere between the two values you should be able to put together a reasonable arguement.


i had the same situation down in melbourne