Page 1 of 3 123 LastLast
Results 1 to 13 of 28
  1. #1
    Join Date
    Jun 2008
    Posts
    2
    Post Likes

    Bryant Evolution System and HRU (Heat Rcovery)

    Question replacing main system in my home with 5 ton Bryant Evolution System. Constractor states Bryant does not reccommend using HRU with their system. Does anyone know and reason why

  2. #2
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    Post Likes
    Manufacturers nevr edorsed them.

    Today with a high SEER system,there is little waste heat to recover,so yo may not be happy with the results,nt close to the water heating capability of 10 SEER or less units.

    Not sure what,if anything official, Bryant has stated.

  3. #3
    Join Date
    Nov 2000
    Location
    Eastern PA
    Posts
    70,420
    Post Likes
    Most likely Bryant/Carrier does not want to have the problems they had when they made their own HRU system a few years back.

    That said, any alterations to the system goes against the equipment manufacturer's desires for their equipment. Can't blame them for not wanting to be responsible for what others have added to their equipment.

    Other than that, there is no reason an aftermarket HRU installed by a professional HVAC person qualified to do that type of install, would not be beneficial for heating domestic water during the cooling cycle of an HVAC system. Why just blow that heat out into the air adding to the global warming issue?
    Training is important!
    Practical Training is a must!

  4. #4
    Join Date
    Apr 2008
    Location
    Northwest Arkansas via Chicago Area via Straight Up from There on Lake Superior
    Posts
    1,411
    Post Likes
    Quote Originally Posted by RoBoTeq View Post
    there is no reason an aftermarket HRU installed by a professional HVAC person qualified to do that type of install, would not be beneficial for heating domestic water during the cooling cycle of an HVAC system
    What would be acceptable aftermarket HRU candidates? Would this be something any good HVAC installer should be able to attach? Can any run on 110 volts since I have no 220 next to the furnace/air handler where I would prefer to install? Also, in mild temps, with heating not fully utilized from the HP, could one run the HRU then (we really only have 1 1/2 months of winter with a few more with the furnace turned on but not really taxed)?

    I am considering a high efficiency dual-fuel unit. I have an HRU option requested from contractors I am having bid but I am getting the old "XYZ doesn't have that option" response. I would like to request that they consider specific aftermarket HRU candidates.

  5. #5
    Join Date
    Nov 2000
    Location
    Eastern PA
    Posts
    70,420
    Post Likes
    Quote Originally Posted by jerryd_2008 View Post
    What would be acceptable aftermarket HRU candidates? Would this be something any good HVAC installer should be able to attach? Can any run on 110 volts since I have no 220 next to the furnace/air handler where I would prefer to install? Also, in mild temps, with heating not fully utilized from the HP, could one run the HRU then (we really only have 1 1/2 months of winter with a few more with the furnace turned on but not really taxed)?

    I am considering a high efficiency dual-fuel unit. I have an HRU option requested from contractors I am having bid but I am getting the old "XYZ doesn't have that option" response. I would like to request that they consider specific aftermarket HRU candidates.
    One problem with HRU's, or desuperheaters, is that they are more commonly sold direct to consumers then through wholesale HVAC distributors. This makes it an item that is not that popular with the professional HVAC installers.

    I would only consider an HVAC installer who has had experience with installing HRU systems before. And yes, heat can be taken from the system during the heating mode but you would need to be certain that you weren't running your heat on electric auxilliary in order to heat your water with the heat pump.

    Desuperheaters should be 120 volts as they are only running a pump and controls.
    Training is important!
    Practical Training is a must!

  6. #6
    Join Date
    Apr 2008
    Location
    Northwest Arkansas via Chicago Area via Straight Up from There on Lake Superior
    Posts
    1,411
    Post Likes
    Found several references in other threads to various studies done in Florida, one by Florida Power, where they speced out HRU's. A little searching on the Internet came up with Doucette and Trevor-Martin Corporation. Unfortunately these seem to require 220 and look like they are located by the outside unit. I would like one inside close to the furnace/air handler. Are any of you aware of other names I could drop to a contractor?

    I am NOT an HVAC guy but the installation looks pretty simple. Just interrupt the hot and cold lines and put the unit in, attach power of course. I assume the HRU has all of the pumps, valves, temperature shut offs, etc. That seem right?

  7. #7
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    Post Likes
    Yeah , could have told you 220 volts,but maybe you can find one that's 120,but I doubt it.

    We have a few that insist,but they aren't happy with the results on high SEER.

  8. #8
    Join Date
    Apr 2008
    Location
    Northwest Arkansas via Chicago Area via Straight Up from There on Lake Superior
    Posts
    1,411
    Post Likes
    Quote Originally Posted by dash View Post
    Manufacturers nevr edorsed them.

    Today with a high SEER system,there is little waste heat to recover,so yo may not be happy with the results,nt close to the water heating capability of 10 SEER or less units.

    Not sure what,if anything official, Bryant has stated.
    Ain't no engineer and don't know much about HVAC but wouldn't newer, high-efficient systems potentially be running hotter refrigerant outside to the compressor and much bigger cooling coils to get rid of? This hotter fluid would be the source of heat for the desuperheater pre-heat of the water heater, no? Seems like the newer HP's could be a better source of pre-heat for the WH?????

  9. #9
    Join Date
    Nov 2000
    Location
    Eastern PA
    Posts
    70,420
    Post Likes
    Quote Originally Posted by jerryd_2008 View Post
    Ain't no engineer and don't know much about HVAC but wouldn't newer, high-efficient systems potentially be running hotter refrigerant outside to the compressor and much bigger cooling coils to get rid of? This hotter fluid would be the source of heat for the desuperheater pre-heat of the water heater, no? Seems like the newer HP's could be a better source of pre-heat for the WH?????
    Higher efficiency systems have lower temperature differential per square inch of coil pack surface area due the larger coils. This is not where desuperheaters get their heat from though.

    The desuperheater gets it's heat directly from the hot gas discharge line which is the same no matter the systems efficiency.
    Training is important!
    Practical Training is a must!

  10. #10
    Join Date
    Jan 2004
    Location
    PA
    Posts
    77,880
    Post Likes
    Quote Originally Posted by RoBoTeq View Post
    Higher efficiency systems have lower temperature differential per square inch of coil pack surface area due the larger coils. This is not where desuperheaters get their heat from though.

    The desuperheater gets it's heat directly from the hot gas discharge line which is the same no matter the systems efficiency.
    The HRU/desuperheaters I've seen all had sensors that dropped out the desuperheater if the hot gas temp leaving it dropped below 120.
    And wouldn't come back on until(I don't remember what temp).
    With higher SEER equipment often times having lower mass flow rates. They could tend to cycle on and off alot. Giving little to no benefit.
    Contractor locator map

    How-to-apply-for-Professional

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

  11. #11
    Join Date
    Nov 2000
    Location
    Eastern PA
    Posts
    70,420
    Post Likes
    Quote Originally Posted by beenthere View Post
    The HRU/desuperheaters I've seen all had sensors that dropped out the desuperheater if the hot gas temp leaving it dropped below 120.
    And wouldn't come back on until(I don't remember what temp).
    With higher SEER equipment often times having lower mass flow rates. They could tend to cycle on and off alot. Giving little to no benefit.
    Hmmm, I need to think about this one. We also need to add the lower rate of compression that is being utilized in higher efficiency systems. My thoughts are still on the fact that a certain amount of heat has to be transferred, no matter what the efficiency of the system transferring that heat is. This is a matter of capacity, not efficiency.
    Training is important!
    Practical Training is a must!

  12. #12
    Join Date
    Jan 2004
    Location
    PA
    Posts
    77,880
    Post Likes
    Lower compressor ratio.
    And a higher mass flow rate then a 10 SEER.

    While the BTUs per hour removed may be the same. The increase in flow rate lowers the temp of the hot gas slightly.
    Just a 5 or 10 lower discharge temp can lower the HRU's ability to heat water.
    So the question becomes. At what temp, does the HRU lose its ability to effectively heat water. To an acceptable temp.

    The warmer/hotter the water tanks temp is, the less efficient the HRU is.
    Contractor locator map

    How-to-apply-for-Professional

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

  13. #13
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    Post Likes
    Yep,they just don't work on high SEER units.

    Now if you want to add a storage tank and use an HRU to preheat the water before it goes to the water heater,you might save some money.

Page 1 of 3 123 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
  •