Page 1 of 2 12 LastLast
Results 1 to 13 of 14
  1. #1
    Join Date
    May 2019
    Posts
    16
    Post Likes

    SEER 38 units - worth it?

    Hello

    there are already some SEER 38 mini split units out there. I wonder how this value is being achieved? Can only be higher compression ratio and higher temperatures they work with, to my understanding. Do you believe these units will last long compared to standard 19 SEER inverters? By the formula I remember the electricity usage should on average be around only the half of a SEER 19 unit, is that correct?

    Did someone of you already install any of these "hyper" units and what are the potential caveats here? I would guess it will be more prone to leaks if there is much higher working pressure.

    Any comments? Thx

  2. #2
    Join Date
    Jan 2004
    Location
    PA
    Posts
    77,535
    Post Likes
    Higher compression ratio would get you lower SEER as the compressor would be working harder, and draw more wattage.
    Contractor locator map

    How-to-apply-for-Professional

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

  3. #3
    Join Date
    Mar 2018
    Location
    Kansas Flatlands
    Posts
    291
    Post Likes
    I was understanding that all multistage, inverter equipment is able to achieve such high SEER is the ratings are taken / mixed with electric consumption / capacity in the lower stages. I E some of the ratings are taken at 72 degrees outdoor, 78 degree outdoor etc. Which is why commercial equipment is rated with EER at 95 degrees. Those who spec that equipment know how to do math and are not manipulated. How's it gonna run when it's hot. Please correct me if I'm wrong.

    The advantage of the inverter is you can size to the heating load and have the heat pump do all the heating with no backup. The lesser cooling load is just runnin the thing at a lesser speed. As far as how long will any equipment built today last? I don't own a crystal ball, but my best guess is not as long as the stuff you're replacing did.

  4. #4
    Join Date
    May 2019
    Posts
    16
    Post Likes
    Thread Starter
    Quote Originally Posted by beenthere View Post
    Higher compression ratio would get you lower SEER as the compressor would be working harder, and draw more wattage.
    they seem to have two stage compressors, so while the combined compression ratio is higher, there is no higher-per-compressor ratio, to my understanding.

  5. #5
    Join Date
    Jan 2004
    Location
    PA
    Posts
    77,535
    Post Likes
    Quote Originally Posted by sepuku View Post
    they seem to have two stage compressors, so while the combined compression ratio is higher, there is no higher-per-compressor ratio, to my understanding.
    Still won't have a high compression ratio to get higher SEER. Whether using 1, 2, or more compressors.

    Lower compression ratio uses less electric.

    First stage will have a very low compression ratio, and second stage will be about normal, to a little less then normal As in close to 3 to 1
    Contractor locator map

    How-to-apply-for-Professional

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

  6. #6
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    9,293
    Post Likes
    Increasing the size of the coils verses the capacity has a major effect on efficiency. Varying the displacement of the compressor to maintain full motor load effects the efficiency. Pressure drop of the refrigerant passing through the refrigerant piping also effects efficiency.
    All of this increases the investment and complexity, which makes pay longer and maintaining more expensive.
    There are few tricks that are unique but "no free ride".
    Interesting.
    Regards Teddy Bear

    Here is good explanation of SEER
    https://asm-air.com/airconditioning/...d-seer-rating/
    Last edited by teddy bear; 05-24-2019 at 01:01 PM. Reason: after thought
    Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
    Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
    Use +Merv 10 air filter. -Don't forget the "Golden Rule"

  7. #7
    Join Date
    Sep 2005
    Location
    Atlanta GA area
    Posts
    39,843
    Post Likes
    Dirty little secret...

    The higher the SEER (or EER)...
    The more perfect (and I mean exactly perfect) the installation must be.

    Lets carry this a step farther...
    Why put a 30-something SEER AC into a house that has single pane windows, poor insulation, and serious infiltration issues???

    I seriously doubt the 30-something SEER would help in that house!
    GA-HVAC-Tech

    Your comfort, Your way, Everyday!

  8. #8
    Join Date
    Jun 2019
    Posts
    11
    Post Likes
    High SEER Value brings so many benefits not only financially but also environmentally. As @ga-hvac-tech said, you should be aiming for better SEER value. Of course, the initial cost will be high but later on your monthly electric dues will be low because of better efficiency.

  9. #9
    Join Date
    Jan 2010
    Posts
    16,003
    Post Likes
    Once it's out of warranty all saving goes down hill quickly.
    Lowering the compression ratio is where the energy saving is.
    Larger condensing coil is how this is achieved or changing the type of coil.

  10. #10
    Join Date
    Sep 2005
    Location
    Atlanta GA area
    Posts
    39,843
    Post Likes
    Quote Originally Posted by VTP99 View Post
    Once it's out of warranty all saving goes down hill quickly.
    Lowering the compression ratio is where the energy saving is.
    Larger condensing coil is how this is achieved or changing the type of coil.
    We sell AlliedAir (Lennox clone)... and ThermalZone (Rheem clone)...
    The former (AlliedAir) just started shipping outside units with aluminum tube coils...
    The price is a tad less than the old copper tube/aluminum fin coils...
    And they are less weight to move around!

    Lets hope this works out... as I am all for the upgrade!

    BTW: All aluminum indoor coils came last fall...
    GA-HVAC-Tech

    Your comfort, Your way, Everyday!

  11. #11
    Join Date
    Nov 2008
    Location
    Piney Flats, Tn.
    Posts
    1,910
    Post Likes
    Just put in a Rheem gas pack and it had micro channel coils for outdoor and indoor.

  12. #12
    Join Date
    Jun 2019
    Posts
    43
    Post Likes
    So how is the high SEER achieved?

  13. #13
    Join Date
    Sep 2005
    Location
    Atlanta GA area
    Posts
    39,843
    Post Likes
    Quote Originally Posted by gustavhorna View Post
    So how is the high SEER achieved?
    This is extremely simplified...

    Larger coils and smaller compressor...
    Having said that... this is only the tip of the iceberg...

    Which, BTW, is part of the reason the price of HVAC is going up....
    GA-HVAC-Tech

    Your comfort, Your way, Everyday!

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
  •