Results 1 to 10 of 10
  1. #1
    Join Date
    May 2018
    Location
    Deatsvills, Alabama
    Posts
    12
    Post Likes

    Still Trying To Connect

    I'm new to this forum stuff and what it takes to become pro certified. can I give you my HVAC contractor licenses number. That would be easier and less painful

  2. #2
    Join Date
    Jan 2015
    Location
    Iowa
    Posts
    1,015
    Post Likes
    Trust me if I can do this, you do this I'm as much a dinosaur as anyone. Getting the 15 technical posts should be relatively easy & painless. Have you had a problem machine you'd like to talk or ask an opinion about in the last week. Filling out the form for pro statusreally takes a couple minutes

    Good luck and come join the pro side

  3. #3
    Join Date
    May 2018
    Location
    Deatsvills, Alabama
    Posts
    12
    Post Likes
    Thread Starter

    Calilation for Return Air Filter Grill

    What is the correct way to measure based on per ton/cfms.

  4. #4
    Join Date
    Mar 2013
    Location
    Billington Heights, NY
    Posts
    20,923
    Post Likes
    Quote Originally Posted by tegriffith View Post
    I'm new to this forum stuff and what it takes to become pro certified. can I give you my HVAC contractor licenses number. That would be easier and less painful
    http://hvac-talk.com/vbb/showthread....nal-Membership

    how to become a pro rated member on this site ^^^

  5. #5
    Join Date
    Jan 2004
    Location
    PA
    Posts
    76,078
    Post Likes
    Quote Originally Posted by tegriffith View Post
    What is the correct way to measure based on per ton/cfms.
    Measure what?
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  6. #6
    Join Date
    Jan 2015
    Location
    Iowa
    Posts
    1,015
    Post Likes
    There are several ways, but primarily: Do the math or use a software program.

    Before I go on, one of the first things to learn about this site is in the open general forum(s) you really don't want to give very specific step by step advise, not because you don't want to share but because you don't want someone who is not quite as skilled or trained to damage equipment or hurt themselves & family. And we don't talk about exact pricing. This site is not a do it yourself site it is here for professionals to share and ask questions of other professionals.

    In very simple terms, back in the day I'd calculate the load and figure out the equipment I needed for the house. I'd figure out what I needed for air flow in each room and make sure I have enough blower fan for the design. Then I'd figure out what my friction loss rate, using manufacturers fan data and the total length of the ducts. Once I had the total CFM and the friction loss rate, I'd grab my handy / dandy ductulator and figure out my duct sizing.

    Anymore I cheat and use a software program. I've seen software programs that will do residential and comercial for not a lot of money in the scheme of things.

    Maybe not the correct way; but by experience after installing a number of units you can get to the point you can say: Yep that unit in this house needs a 20 x 14 return grill . The times I've used experience I will typically go back and calculate the size before I get it installed

  7. #7
    Join Date
    Aug 2009
    Location
    Prattville, Alabama
    Posts
    3,319
    Post Likes
    Tegriffith, you're located near me! It's very easy to become a pro member here. You can join discussions that are currently underway, if you like. Share your opinions and experiences. Ask questions, maybe for clarification. Check out the link that HVAC_Marc provided. It has the requirements, and how to go about it. Proving you're a "Pro" is more about proving you make a living at it than proving you're some kind of expert. So don't be intimidated, or overthink it, lol.

    And Welcome!

  8. #8
    Join Date
    Mar 2013
    Location
    Billington Heights, NY
    Posts
    20,923
    Post Likes
    Dont worry! Im one of the guys looking at your documents.

  9. #9
    Join Date
    May 2018
    Location
    Deatsvills, Alabama
    Posts
    12
    Post Likes
    Thread Starter
    400 cfm per ton
    3 ton system = 1200 cfm
    1200 divided by 2 = 600 sq. in. of filter back return grill

  10. #10
    Join Date
    Jan 2015
    Location
    Iowa
    Posts
    1,015
    Post Likes
    400 cfm per ton
    3 ton system = 1200 cfm
    1200 divided by 2 = 600 sq. in. of filter back return grill
    That's rule of thumb, I agree rule of thumb guidelines do have some basis in real fact, and many times work OK, but are not always correct. What if you don't have that much room can it be smaller? By how much before you have a noise or performance issue

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Related Forums

Plumbing Talks | Contractor MagazineThe place where Electrical professionals meet.