Interesting Air Distribution problem.

[thien2002]

Please help me with this problem:
In our storage warehouse (70'Lx30'Wx30'H), we have problem with air distribution. We don't have any heat below 14' High. Our return air (Louver) located about 25' above ground and so our duct space diffuser. I am thinking that maybe Returned air is the same Elevation with Supply Air Diffuser so the Supply Air is forced right back to Return Louver.

I am planning to lower the Diffuser elevation about 5' and the Return Air Louver to ground level (3' above ground). Please let me know if any of you have dealt with situation like this before. Thank you!

 

[wilg]

Stratification of heat layer and short cycling
of supply going directly into the
return all rolled into one problem.
Sounds like your on the right track,
lowering the return 3 feet above finished
floor you will solve
both aspects of your problem.
If your lowering the supply 5' from
present position, I have to ask...
Do you have anything stored above
the new proposed supply air level ?
Are the goods being stored required
to have temperature and humidity
control within tight limits ?

 

[cme]

What type diffuser do you have? Look to apply something that is downblow. Anemostat makes a C-27 which I use in school gymnasiums.
For high spaces, locating the return down low works fine.

 

[ChrisConley]

To combat stratification you could also consider using a large ceiling fan. Check out:

http://www.bigassfans.com/

They have a wide variety of products for your application.

 

[thien2002]

You all are so helpful, I think I will use the destratification fan (bigass fan) to move heat of 140,000 cfm. What do you think? Again, thank you so much for everyone's time.

 

[CyrusP81]

Can you consider spot-heating with radiant heat? If you need the heat in the rest of the warehouse for freeze protection, then go with your original idea. If it's not needed for freeze protection (either the stored product can handle it, or you don't get that cold where you're located) scrap the whole tham dang, and put a radiant heater at each position that is regularly occupied by a person. With radiant heat a person can feel comfortable with air temperatures as low as 55° F.

 

[jherbert]

This is a classic stratification problem,
covered in many text books. I would suggest
a number of smaller fans for better distribution.

A quick search on google should give you
plenty of options and lower energy bills too

cheers,

 

[thien2002]

Guys, thank you so much for reply to this post, I already have fixed the problem by lowering air intake, increase heating temperature by 5F.

 

[ChasBean1]

Thien2002, actually you put a band-aid on the problem at the expense of energy use and ventilation.

I second (or third?) the notion of destratification fans throughout. These can be automatically controlled by thermostats placed strategically high and low and taking an average difference to energize and/or control destrat fan speed.

That would be a fix. Modifying air delivery and return locations would also be a fix. Vr, -CB