Diffuser Layout for High Ceiling Applications

[Matt_1997]

Diffuser Layout for High Ceilings

I am doing a design for an industrial building that will have high exposed ceilings ranging in height from 20-40 ft. I usually leave it up to an experienced drafter to place diffusers for standard commercial applications with 8 ft ceilings; however, with high ceilings, is there anything I need to pay attention to in terms of diffuser throw, drop, etc. In some of these spaces, the air will be used for heating and cooling. Some general questions:

•I understand that in cooling you want to minimize drop to avoid uncontrollable drafts and allow natural stratification to occur.

•But when we are heating with the air for high ceiling applications, do you want to select diffusers with high throw (I.e. price drum grilles) with them angled down to ensure the warm air gets down to the occupied space?

•Are Price round cone diffusers suitable or do you guys use a specific diffuser types for these applications?

•Any general guidance on diffuser spacing (not specific to high ceilings)?

Maybe the air distribution is more forgiving than I think and perhaps I am overthinking it but I am open to any tips anyone has to offer!

TLDR: tips for diffuser layout for areas with high (20-40ft) ceilings when using the air for heating.

Thanks.

 

[AxisCat]

I am not an Engineer but a contractor with lots of years experience. There is probably some math you can throw at it in terms of supply air temperature and jet velocity from your registers but bottom line is warm air rises. You are on the right track with downward facing registers with a high throw to get that warm air down. Industrial settings are not normally as critical as say an office space where a person is sitting in the same spot all day long. Contact your local Price representative and they can probably help you with your air device selection.

 

[HVAC-Novice]

if you want to heat and cool adequately in high ceiling, diffusers aren't ideal.

It depends on your discharge air temperature. Or more specifically, the dT to room temperature. if you discharge at 100F in a 60F space, this won't work well.

Much more information required.