Condensate Drain Trap!

[Rustyowls]

Ok....we recently installed an air handling unit (14,000 cfm, approx 6.5" total static, 3.5" at the trap, draw through unit).

The issue is the unit is squeezed in a basement, and couldnt be provided with a baserail. as such, we only have a 4" housekeeping pad. Obviously this wont allow for the proper trap height - depending who you ask it should be either 4.5" or 6.5". Anyway, is there such a thing as a condensate pump for a large air handling unit?? I've seen them for fan coils, but dont know if they exist for large AHUs. Any ideas?

 

[imok2]

This may be a solution:

http://www.libertypumps.com/data/tbProducts/12_model260.pdf

 

[quark]

Can you take the pipe straight out to the drain chamber and create a trap there?

 

[tombmech]

imok2 and quark both offer good possibilities. I would add that Liebert computer room units can come in some large tonnages. Yet, a pumped condensate is an option on all of them.

quark kind of touches on my real opinion, though. I'm not sure it's really that important. Condensate drains typically drain with an air gap to a floor drain, and are not directly connected to pipe. That removes some of the necessity for a trap (no sewer gas). It is actually more important to have the vent. It is also a good practice to place a stainless steel drain pan around the unit with its own drain to condensate as well. Backups happen regardless (probably more often with the trap!), and a drain pan creates a berm that offers additional insurance against condensate floods.

You can always fabricate whatever trap dimensions you want, or even roll the elbows to give the same effect within your available clearances. Depending on the length of run to your floor drain, you may not need one at all.

 

[ChrisConley]

At the AHR show this year in Chicago there was a device that allowed condensate traps to drain down against very high static with very little drop.

The device looked like snorkle with the cage and ball.

The demonstration showed it draining against a sump against ~5" of static w/about 2" of drop. The sump also had a 4" standard drain that was sucked out by the pressure.

The reason I'm spending so much time describing it is that I can't remember the name and I was hoping this would jog my memory... anyone else see it at the show?

You could probably search the AHR presentors database. I'll probably check as well.

 

[walkes]

Is this it?

http://www.drainplus.com/

 

[ChrisConley]

That was it exactly, thanks walkes.

 

[tombmech]

That's a neat device. My bad, Rustyowls - I believe you were referencing the trap dimension as the minimum head to overcome the static of the unit. I didn't realize that in my first post.

 

[walkes]

Rustyowls,

If you are still looking for a condensate removal pump, Little Giant makes some nice low profile units.

http://www.lgpc.com/Product/ItemDetail.aspx?ProductID=211

 

[Rustyowls]

Thanks Guys....my problem is there is literally only 3 1/2-4" to work with in the vertical dimension to the floor.

Then the line runs parallel to the unit out of the building.

These pumps might be our only answer. My question with the pumps is do they have a large enough pumping capacity to remove condensate from a 14,000 cfm AHU? I always thought the Little Giants were more of a FCU type of pump.

 

[ChrisConley]

Take a look at the website walkes listed Rusty. They show a trap being made against high static without the required depth. There is a good video showing exactly how it works.

I'm not saying it will work in your situation, but it looks like it might.

 

[Rustyowls]

I checked out the video...this is indeed very cool. I will contact them and find out. My only concearn is the demonstration is against 2" of negative static...we're looking at 4-5" depending on filter loading.

If they dont have this thing for higher static applications, they should start designing now!

 

[CarolinaPE]

I've used a Little Giant on several jobs, make sure you follow the mfg recommendations for the line size out of the pump (it is small!). Also, check the height of condensate outlet on the unit, usually it is a few inches vertical.