Page 1 of 2 12 LastLast
Results 1 to 13 of 17
  1. #1
    Join Date
    May 2007
    Location
    DC Metro Area (MD)
    Posts
    3,371

    Do installers usually adjust the airflow?`

    Was wondering what the general consensus on this was, with input by both techs and installers. I was talking to someone I know who happens to do installs, and he didn't seem to realize the importance in adjusting anything from factory settings. An 80k/3 ton furnace with a 2 ton condenser would then be getting 600 cfm/ton (or whatever the ductwork would handle). He thinks of it as just airflow over the coil, and wouldn't bother adjusting anything. Is this usually the case you find? With variable speed blowers this would be especially important. That's why there are dipswitches. Makes me think twice about recommending a larger air handler for improved efficiency if its just going to be left at its 5 ton airflow setting, or whatever it may be, with a 3 ton condenser.

  2. #2
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,323

    Unhappy Depends on the Tech ... as always and ...

    Quote Originally Posted by RyanHughes View Post
    An 80k/3 ton furnace with a 2 ton condenser would then be getting 600 cfm/ton (or whatever the ductwork would handle). He thinks of it as just airflow over the coil, and wouldn't bother adjusting anything. Is this usually the case you find?

    Makes me think twice about recommending a larger air handler for improved efficiency if its just going to be left
    You'll find many who can not discern the true
    differences between air, error and ear.
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

  3. #3
    Join Date
    Mar 2005
    Location
    Houston, Texas
    Posts
    11,874
    I'll say none, if any. Unless they're told to. And how to do it. (not meant in an insulting way)

  4. #4
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,299
    From what we see, almost all are left on high for cooling. Every time we get a new installer he wonders why we take static readings and the install paperwork has instructions on speeds. Most are shocked if they are told to put a blower on low!

  5. #5
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,311
    Same here. Lots of blowers are left on high no matter what size A/C is installed.
    Contractor locator map

    How-to-apply-for-Professional

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

  6. #6
    Join Date
    Mar 2007
    Location
    Myrtle Beach, SC
    Posts
    2,919
    However it comes from the factory is how it is left. I went on a survey two days ago and measured air flow. When I delivered the bid yesterday, He said I was the only one of 3 bidders who tested air flow.

    Our new power company program is going to require air flow testing. I am on the advisory board and have been pushing for that for years. November 1 it starts. Low interest loans and an up front rebate for the homeowner. The power company is going to provide training for the contractors who wish to be involved.
    Remember, Air Conditioning begins with AIR.

  7. #7
    Join Date
    Aug 2009
    Location
    Beatrice, NE
    Posts
    2,268
    We have a progran with the power co that gives a rebate to the customer only after the system is tested and adjusted to <10% of manufacturer rating. A power co rep told me that some of the dealers can't even fudge the number right. Go figure!!

    As for us we test and adjust every install!

  8. #8
    Join Date
    May 2004
    Location
    south louisiana
    Posts
    3,231
    I agree, most leave dipswitches on factory settings..even here where lowering the fan speed makes a dehumidification world of difference.
    too many folks think that variable speed is going to solve all the issues.
    its like this in many industries..foam insulation companies promise
    'total encapsulation systems', but do not test the jobs when completed..and want to argue with you when you do test.
    people have to have the want to do better, the ones who don't..make more work for those of us who do.
    good to see you Ryan...ever think about changing employment?
    as I seem to remember..you are a home owner who had to self educate to get a good
    install??
    The cure of the part should not be attempted without the cure of the whole. ~Plato

  9. #9
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,323

    Smile Nice to here about SOME Progrsss

    Quote Originally Posted by Kevin O'Neill View Post
    \\

    When I delivered the bid yesterday, He said I was the only one of 3 bidders who tested air flow.

    Our new power company program is going to require air flow testing.

    The power company is going to provide training for the contractors who wish to be involved.
    Power company is Progress Energy _ _ _ _ _?
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

  10. #10
    Join Date
    Mar 2007
    Location
    Myrtle Beach, SC
    Posts
    2,919
    Quote Originally Posted by dan sw fl View Post
    Power company is Progress Energy _ _ _ _ _?
    No Dan, It is Santee Cooper. But I understand that Progress Energy is bringing some similar programs back. But I don't work in their service areas.
    Remember, Air Conditioning begins with AIR.

  11. #11
    Join Date
    Jul 2008
    Location
    Rochester NY
    Posts
    4,739
    The customer generally gets what they pay for. Many homeowners go with low bid. Low bid generally means no heat loss, no blower door (so total guess at sizing), no mastic, slam the furnace in and go. Definitely no balancing - no time in the budget for that!

    Orphaned water heater? No worst case CAZ either.

    Another nice thing about the Infinity - tells you static and airflow at each stage.
    Which makes more sense to you?
    CONSERVATION - turning your thermostat back and being uncomfortable. Maybe saving 5-10%
    ENERGY EFFICIENCY - leaving your thermostat where everyone is comfortable. Saving 30-70%

    DO THE NUMBERS! Step on a HOMESCALE.
    What is comfort? Well, it AIN'T just TEMPERATURE!

    Energy Obese? An audit is the next step - go to BPI.org, or RESNET, and find an auditor near you.

  12. #12
    Join Date
    May 2004
    Location
    Southeast US
    Posts
    24
    A long time ago a misinformed guy, who was an otherwise excellent tech.....told me 'a little extra airflow won't hurt , it will help overcome the duct system'.

    Of course that's not what we want to do.

    Problem is...it blows the moisture off the coil..often creating MOLD. And more noise!

  13. #13
    Join Date
    Dec 2002
    Location
    in a house, Appomattox, Va.
    Posts
    3,318
    didn't first few yrs in install. wouldn't leave a job later w/o doing airflow as part of startup. Even when replace motor or feel there's and issue will check on service calls as well.
    Col 3:23


    questions asked, answers received, ignorance abated

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event