JFGI

Impulse or jet fan: An axial fan with a high velocity discharge that induces air flow in a long underground tunnel without ductwork

http://www.greenheck.com.cn/gks_content/pdfs/produ...

As for calcualtions, that will be code based. Ususally low exhaust during normal conditions, and a higher rates of exhaust when carbon monoxide levels get high. (something like 1.5 cfm/sf from memory).

knowledge is power

Thx,

Can you tell how do i place them? i mean positions of jet fans, should i place them at the points where i have placed diffusers or place them in such a way that diffusers come in between??

diffusers would be installed on ducted ventilation systems so, I am a little confused by your statement that your client wants no ducts.

Perhaps its time for the OP to engage the services of an engineer who is familiar with the technology that the client has expressed an preference for.

I am not good in communications,
but this attachment might help me to explain what i want to say

Here is the link

• http://files.engineering.com/getfile.aspx?folder=436fa12d-c02a-4c50-9ade-fc

Im sorry I read an underground garage, not basement (so cancel my carbon monoxide comment).

Exhaust rates will be per ventilation code (Ashrae 62?)

As for location, it all depends on the layout. Assuming large rectangular box? Intake on one side and exhaust fan on the other? Or am i oversimlifying it? If you use a jet fan underground and dont duct it, how can you push air above ground and outside? And if you bring in outdoor air as youyr intake how do you condition it.

Just because the client wants it, doesnt mean he knows what he wants or what is good for the buulding (or of ot meets code). What is the reasoning for the jet fans? Is it cost? Im sure with minimal duct and less expensive type of fan, you can provide a less expensive option that will work better.

It is your job as the engineer to provide hime with that info.

knowledge is power

The PDF drawing has much to be desired as I can not make head from tail about the relative positions of the jet fan diffusers and the ducts.