VAV BOX SIZE

[pavlik]

Before I call my Anemostat rep,
I just wanna know what other engineers typically specify when it comes to sizing VAV boxes. What's the largest possible CFM through a VAV box for open office layout, interior/ perimeter zoning?

thanks

 

[remp]

Your VAV box can be any size, however a few things which dictate the size are,
1. Space requirements, is there enough height in the ceiling space to facilitate the box
2. Noise criteria, the bigger the box the more the noise generally speaking
3.Temperature control. One hugh box serving a large area does not give you as musch flexibility and control regarding temp as a number of smaller boxes.
4. Costs - The more boxes the higher the cost, not just ductwork and boxes but also control and BMS , which is usually as much.

A good rule of tumb would be 1 box to serve 100m2-150m2 approx, but it is up to your client. If you have a nunmber of offices, does your client want 1 box per office or 1 box per 4 offices, which is also fine but your client may have the money to spend and might like the first idea.
Its usually down to money so if you give 1 per 100m2 on the perimetre and 1 per 150m2 for centre zone you cann't go too wrong

Good luck

 

[SAK9]

A high quality office would have one VAV box for two diffusers each delivering about 400cfm o the perimeter soon.For the interior about foor diffusers/box gives ggod control.

Generally the bosses like to have their cabins on the perimeter with a view.Therefore a few extra boxes on the perimeter will come in handy