Is Displacement Ventilation a Viable Option for Cooling in the Northeast USA?

[Artman]

Any of you HVAC guys/gals design a Displacement Ventilation (DV) system in the Northeast USA?

With our heating requirements as a notable concern, is DV a viable option for very many applications in the NE USA (DE, NJ, PA areas).

It looks interesting to me especially for cooling, but I think adequate heating may be a concern. Anyone have any experience with it?

 

[Artman]

Here's a link to a http://www.price-hvac.com/catalog/J_all/SectionJ.aspx?pageRequest=INTRODUCTION" I found on the subject. It seems DV is geared more to cooling dominated spaces.

 

[russ_watters]

If a data center system qualifies, then I have...but as you say, that's a cooling only system.

 

[mugaliens]

Hi, Artman. I'm not sure what you're trying to accomplish. I've done HVAC work in FL, LA, NV, and CO, on a contractual basis.

 

[Artman]

If a data center system qualifies, then I have...but as you say, that's a cooling only system.

I think the difference between data center cooling and what I am talking about is that the objective of DV is to not interfere with natural stratification of air, but to enhance it. DV seems to use lower velocity to avoid entraining and mixing old air with air being introduced through the HVAC system. Also, it uses higher, slightly below room temperature air (min of 65 deg F).

mugaliens, I don't currently have a project that suits this type of system on the boards, just researching it now. The areas you mentioned seem well suited to it. You should check it out.

DV systems, from what I read, can use 25% less outside air, because of more efficient distribution and resulting increased IAQ. And the higher delivery temperature air requires less energy to produce. It seems like an interesting system if it can be made to work in heating mode for my area.

 

[mugaliens]

I think the difference between data center cooling and what I am talking about is that the objective of DV is to not interfere with natural stratification of air, but to enhance it. DV seems to use lower velocity to avoid entraining and mixing old air with air being introduced through the HVAC system. Also, it uses higher, slightly below room temperature air (min of 65 deg F).

Bingo, and not "seems to," but definitely. It's a minimal flow rate system designed for large spaces (think of movie theaters, warehouses, and older gymnasiums, particularly those in hotter climates), and requires natural stratification to be effective. The reason it uses below normal room temp air is to ensure that air from contamination sources (people, equipment) rises to the upper levels where it's extracted.

It works for cooling, but not for heating, as hot air rises!

mugaliens, I don't currently have a project that suits this type of system on the boards, just researching it now. The areas you mentioned seem well suited to it. You should check it out.

Some areas in the NE can use it, but again, it's a cooling system, not a heating system.

DV systems, from what I read, can use 25% less outside air, because of more efficient distribution and resulting increased IAQ. And the higher delivery temperature air requires less energy to produce. It seems like an interesting system if it can be made to work in heating mode for my area.

Er... It's not a heating system. Again, it's for large spaces, and requires stratification, whichis disturbed by heating.

 

[Umesh299]

I am currently working on the Displacement ventilation project and looking on the ways to arrive this 65deg Supply air temp. thru bypass of the air. Do anybody know the details of the calculations.

Bingo, and not "seems to," but definitely. It's a minimal flow rate system designed for large spaces (think of movie theaters, warehouses, and older gymnasiums, particularly those in hotter climates), and requires natural stratification to be effective. The reason it uses below normal room temp air is to ensure that air from contamination sources (people, equipment) rises to the upper levels where it's extracted.

It works for cooling, but not for heating, as hot air rises!



Some areas in the NE can use it, but again, it's a cooling system, not a heating system.



Er... It's not a heating system. Again, it's for large spaces, and requires stratification, whichis disturbed by heating.