what vent distribution do I need for my space? 1

[newdoc]

I'm moving into an office space of about 2600 sf.
the configuration of the space currently is an open rectangular box approx 40'x70'.

The HVAC unit is supposed to be adequate to regulate temperature to this space. However, I am concerned that a single in and out will not maintain constant temperature throughout the space.

How many intakes and outputs would I need to adequately distribute air to this space to maintain temps per ASHRAE?

 

[KiwiMace]

Primarily, that depends on the type and size of diffuser you find most architecturally pleasing for the space.

Download, say, the Titus catalog

http://www.titus-hvac.com

(or any other brand you like) and look up diffusers. Square ones are common if your ceiling is gridded out, or if you don't plan on having a ceiling (which might be likely if you can't afford an HVAC engineer) you might look at registers directly from the duct.

As this is the purely subjective part (note the use of the word Architecturally above) you may get a dozen responses all telling you a different thing.

The diffuser you choose will have a range of airflows for the space you want. This will affect noise and throw (how far the air particles go and how fast). Take into account drafts, variable loads, supply air temp, duct layouts, high load zones, solar effects, lighting & fire protection layout, supply ducting, outdoor air requirements, the little old lady who took off her sweater sitting near the south facing window, location of the thermostats, interior layout, full height walls, return ducting, envelope losses, noise of a different type, and then go hire the HVAC engineer.

Good work on correctly identifying ASHRAE as the standard bearer. Typically, your final solution would have more outs than ins.

 

[newdoc]

Thanks for the reply.
I imagined that there would be a host of variables that ultimately determine the number, type and location of diffusers, etc. placed within the space.

However, is there a simple way to estimate in a basic 40x70 box what the standard distribution chain(?) would involve?

for example, to properly cool a generic box that size, I would be ok with one intake, but would need 4 (or 6, or 8) outs spread evenly throughout the space for adequate temperature regulation....

Thanks again for the insight!

 

[KiwiMace]

No, there is no generic solution to your problem.

Unless... the space is a mid-level floor of a multi-story supplied from a common system, then you can probably copy from another mid-level floor (not upper or lower).

An HVAC engineer would calculate the load using software, then divide this into sub-zones splitting up the various facing window zones from the internal zones. The peak airflow to each zone can be readily determined from this peak load if you know the design criteria of the HVAC equipment supplying the air.

With HVAC, things are not as they appear. A diffuser near a window, may be set to deliver 2-3 times the amount of air than to a seemingly identical diffuser in the middle of the room.