Page 2 of 2 FirstFirst 12
Results 14 to 21 of 21
  1. #14
    Join Date
    Feb 2011
    Location
    Georgia
    Posts
    836
    Post Likes
    Quote Originally Posted by HAWK 87 View Post
    Bruh! I cant even. You think a guy that does a beautiful install like this dont know how to check static. This guy practically invented static. Beautiful work as always johoff34.
    Im not questioning his beautiful work. Im questioning the TESP. That evaporator coil and filter cabinet are exerting over .3 combined at 800 cfms. Im ASSuming its a 2 ton unit to be conservative. You must not do a lot of static readings on your installs to believe a .45 is realistic with that set up.


    Sent from my iPhone using Tapatalk

  2. #15
    Join Date
    Feb 2011
    Location
    Georgia
    Posts
    836
    Post Likes
    By the way Im asking questions because it make us all better. My experience with carrier coils is always over .2 and my experience with the 413 April aire is over .1 at 800 cfms. Your set up looks to be a 2.5 ton. So at 1000cfms Id guess close to .2 on the media cabinet. My ASSumption is the coil and media cabinet are exerting over .4 by themselves. So If Im right, the only way to get a .45 is to have no ductwork attached.

    Like I said, this kind of stuff helps us all be better techs. And if this is correct, further proves why we need more fittings that lower the TEL of the duct system.


    Sent from my iPhone using Tapatalk

  3. #16
    Join Date
    Mar 2014
    Location
    Grand Blanc
    Posts
    561
    Post Likes
    Thread Starter
    The is total static. Its a 2 ton AC. That static is actually high heat airflow, closer to 1000 cfm. The static is taken before the coil and after the filter. If you look closely you can see the test plug in the transition between coil and furnace, and in the bottom door of furnace near the site glass. The original ductwork is larger than required for a 60k and 2 ton that helps with a low static. Original furnace was 110k and 4 T ac.

  4. Likes chrisevansac, BALloyd liked this post.
  5. #17
    Join Date
    Mar 2014
    Location
    Grand Blanc
    Posts
    561
    Post Likes
    Thread Starter
    .13 Filter drop, .14 coil drop, .1 supply duct, .1 return duct.

  6. Likes chrisevansac, kdean1 liked this post.
  7. #18
    Join Date
    Feb 2011
    Location
    Georgia
    Posts
    836
    Post Likes
    Quote Originally Posted by johoff34 View Post
    .13 Filter drop, .14 coil drop, .1 supply duct, .1 return duct.
    Thats amazing. When using a Plenum box for return and flex run outs, im getting Close to .2 on that size media cabinet. This is a 2.5 ton coil or 2 ton? Im getting mid .2s across a 2.5T coil (wet) with plenum and flex 1000 cfms


    Sent from my iPhone using Tapatalk

  8. #19
    Join Date
    Mar 2014
    Location
    Grand Blanc
    Posts
    561
    Post Likes
    Thread Starter
    Most homes here are all metal trunks, round metal supplies and panned returns. They also leak like a siv, causing plenty to feel their installs are adequate but in reality theyre not. I sealed all the accessible ductwork in this home, sure plenty still leaks but much better than it was. What I have found works best to have a low TESP is to concentrate entirely where the air enters and exits the equipment. I have been installing 6 transitions between my furnace and coils the last year or so, I believe it helps and also gives me a great spot to check static. I use radius elbows as long as the throat is 6 if not I install turning vanes. Anything 80k, 3T and up gets a 6 box and 20 media filter, I find that helps drastically. I would probably have a larger filter say 25x25 if I did a 5 T just havent done one yet on my own.

    The new systems Ive done I use all metal trunks, round metal supplies and wall stacks in the walls for returns going to round pipe back to the trunk. Using all metal returns I find my static runs higher, usually around .2 for return side, but as long as I follow the rest of the guidelines I can get out between .5 and .7 static at high airflow, I typically always have multi stage equipment w/ ECMs. Right now Im doing an attic job, metal trunks w/ flex run outs, 80% furnace so that should help. Very interested in how it comes out. My first one on my own.

  9. #20
    Join Date
    Feb 2011
    Location
    Georgia
    Posts
    836
    Post Likes
    Makes sense though. With the spacer between the furnace and coil you give the airflow time to straighten out a little, less turbulence means less static. Same with the radius EL


    Sent from my iPhone using Tapatalk

  10. Likes ga-hvac-tech liked this post.
  11. #21
    Join Date
    Oct 2011
    Location
    Culver, Oregon (Central OR)
    Posts
    2,674
    Post Likes
    Hmm, I may steal that. There are some manufacturers that recommend the spacer but I haven't made it practice to do it on all of them.

Page 2 of 2 FirstFirst 12

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Contracting Business
HPAC Engineering
EC&M
CONTRACTOR