Replies

1. 
   oops | Apr 06, 2011 11:43pm | #1

   EC

   I think the term you are looking for is "plenum". In you case it would be the "supply plenum". 

   That might have been a better way of doing it, but I don't know if installing what you are calling a collar would help that much as long as the connections are tight, secure and  the air flow is not restricted, 

2. 
   DanH | Apr 07, 2011 06:48am | #2

   Either plenum or manifold is fine.

   Yeah, it's not the greatest install, but not clear that it's a problem.  In a regular HVAC system you wouldn't want such connections in an "unconditioned" attic as the leakage (even if relatively small) would cost $$ and possibly cause condensation in the attic, but for a swamp cooler it doesn't seem like it could be any great loss.

3. 
   Yossarian99 | Apr 07, 2011 10:09pm | #3

   Thanks for the replies and the clarification on the terminology.  No profession or discipline is complete without its own terminology.

   When the last snow is behind us in my part of the country I plan on taking a better look from above and see how they attached the flexible duct.

1. 
   DanH | Apr 07, 2011 10:22pm | #4

   Probably your biggest potential problem is in heating season when air would want to move back up those ducts.  Presumably there's a shutoff damper somewhere in the setup, but you could have warm air leaking out of those joints if ducts aren't shut off at the ceiling.

4. 
   Tim | Apr 08, 2011 03:36pm | #5

   Terminology

   One, the large distibution box is called a plenum.

   You are correct, ducts are usually connected to plenum in one of two ways - with a "take-off" or a "duct collar".  The ones shown in the photos appear to use a duct collar. The item (a crimped or straight duct collar) is very inexpensive and readily available at most home centers and full service hardware centers.

5. 
   Clewless1 | Apr 09, 2011 09:08am | #6

   Yes, plenum.

   Standard detail would be to install a standard collar for which to attach the ducts to. You could seal the colar and also the ducts if you need and attach them w/ a standard collar band (not sure if that is the right term). Someone did yours on the cheap and maybe forgot the collars at the shop. Also evidenced by the use of flex duct (IMO). As a rule, I tend to just say 'no' to flex duct; but that's another topic.

1. 
   DanH | Apr 09, 2011 09:22am | #7

   This is a swamp cooler, after all.  Using something other than flex duct would be like putting alloy wheels on a Yugo.

1. 
   Clewless1 | Apr 09, 2011 06:07pm | #8

   I disagree. If you are going through the trouble of moving air at all, you might as well do it efficiently. And rigid duct isn't the same as alloy wheels vs. steel IMO.

1. 
   Yossarian99 | May 11, 2011 05:31pm | #9

   Update

   Looking down into the plenum from the swamp cooler on the roof I saw that the flexible duct was just stuffed into it.  I'm not one for leaving something like that be, so it was the project of the day, cold and rain here anyway.

   The holes in the plenum were 11 1/2" in diameter, hand cut.  Look at pic #1 and you will also see the original holes are to close to the rafter to allow proper attachment of the flexible duct, always something.

   Installed three collars and sealed to the plenum with duct sealer, ready to attach the flexible duct.

   I would prefer rigid ducting, but untill we decide what to do with this home long term, the original flexible duct will stay.

   Also there are registers on the ceiling that have a damper to close off the swamp cooler in winter.  Not very tight though, another project.

6. 
   Clewless1 | May 12, 2011 12:26am | #10

   Sounds like reasonable judgements. I'm doing a little of the same. Attic w/ flex duct for the E/C. Trying to determine if it's worth the hassle to install rigid for at least some of it and get it out of the way of the catwalk at the same time. It sure is a pain to correct someone's decision to do something substantially less than good.

   Hey we gots to pay our money and take our choice.

7. 
   JASP521 | Mar 24, 2016 04:04pm | #11

   Flexible Ducting

   I also plan to distribute air from a swamp cooler through flexible ducting to a few different rooms. Can anyone tell me if there is any risk of bacteria or other potential respiratory issues when putting this high moisture air (swamp cooler) through this ducting? Thank you.