Page 1 of 4 1234 LastLast
Results 1 to 13 of 45
  1. #1
    Join Date
    Jul 2008
    Location
    New Jersey
    Posts
    24

    Replacing 2 systems with one, considering Carrier or Lennox hybrid gas/heat pump

    My questions for you professionals are so I can make an informed decision and I highly value any advice. I am not a DIYer.

    My current HVAC plant which is about 20 years old uses 2 Rheem 105k oil fired furnaces, and two 2.5 ton Amana AC units. One for system for each floor of the house. My neighbor had a similar "2 of everything system" replaced by a single 5 ton Carrier Infinity heat pump and a single multi burn variable speed gas furnace, and they turned his 2 zones (up/down) into 4 zones, presumably with dampers. I am considering a similar system now that gas service is available on my street. My neighbors heat pump is Carrier's Infinity line, is supposed to be top of the line in terms of efficiency and durability. His uses a 2 stage scroll compressor. Carrier also offers the same 5 ton capacity in a unit with a 2 stage reciprocating compressor. The scroll seems to be slightly more efficient than the reciprocating, but again both are 5 ton. So the first question is: which type of compressor is best? Next question: is a hybrid system really going to pay for itself, or should I just go with a gas furnace/AC? And I guess my final question is, is my "2 of everything, one for each floor system" an antiquated system and is it wise to replace it with a big scalable system like my neighbor. And any preference on Carrier or Lennox, or any other suggestions are appreciated too.

  2. #2
    Join Date
    Mar 2005
    Location
    burlington county n.j.
    Posts
    9,743
    it could be done and made to work fine with one system but i would prefer to have the 2 seperate systems.

    in any of the high efficiency equipment the smaller units of the same model are always more efficient than a 5 ton unit is.

    with 2 systems if one goes down you have the other section of the house to "hide out" until repairs are made.

    4 zones on a 5 ton system is more than likely to end up with undersized zones that will require a dump zone or even if the controls slow the blower down enough the a/c unit or furnace will probably be short cycling on the discharge air sensor.



    i sell Lennox so what one do you think i prefer............

  3. #3
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    Opposite viewpoint here.

    I prefer zoning systems,only one each to maintain and replace down the road.

    Your getting 4 zones instead of two,better controll of room to room temperature,better use of setbacks for unused areas,quicker response from setback of less then all zones,and extra capacity in a zone for parties,small ones ,not large.

    the only good point ,IMO,about two systems ,is if one is done,you very likely have the use of the other.

    The Infinity zoning is well equiped to handle retro fitting of a zoning system,better then most.However it can't overcome severely undersized ducts,best that they check the duct system ,before install.If your neighbors is working well,chances are yors will,assuming the same HVAC guy did both homes.

    Hybrid heat,Carrier system is really nice,gives you a fuel choice ,based on price of each,as prices can change.

  4. #4
    Join Date
    Jul 2008
    Location
    New Jersey
    Posts
    24
    This is the input I was hoping for. Having lived with my dual system for 18 years I know the advantage of having redundancy. The down side of having 2 systems is maintaining them.

  5. #5
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,156
    If you are running 4 zones, I'd prefer the Bristol TS and its 50%/100% staging to the scroll which is more like 75-80% on low. That way when 1 zone is calling, you aren't trying to force as much cooling into 1 small duct.

    I would think the Infinity zoning would be the way to go over any other when you are trying to do what you are doing vs starting from scratch and properly designing a duct system.

  6. #6
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,058
    2 systems is nice as you do have a back up if one system fails during the night. You can make due on the one that is still working.

    If going with one system and four zones.
    The Bristol TS, with Infinity zoning would be my preference.
    Contractor locator map

    How-to-apply-for-Professional

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

  7. #7
    Join Date
    Jul 2008
    Location
    New Jersey
    Posts
    24
    I could live with just the 2 zones, up and down. We have been living that way for years, and it's already ducted that way. It was my neighbor that had his up/down 2 zones split to 4. It's only my wife and I, and we zone off unused rooms simply by closing doors. Works for us. For some reason I thought the Carrier had a Copeland scroll compressor, which I read has excellent reliability. I had to Google that Bristol compressor as I had never heard of it. That thing scares me. Looks like a lot of moving parts. http://ts.bristolcompressors.com/cts.html Is that considered a reciprocating compressor? I know the Lennox I was considering does have a Copeland 2 stage scroll. What brand uses the Bristol TStechnology?

  8. #8
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,058
    Carrier has 2 lines of the Infinity 2 stage.
    One uses the Copeland scroll, the other the Bristol TS.
    Yes, its a recip.

    They have been out for awhile now, and are proving reliable.
    Contractor locator map

    How-to-apply-for-Professional

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

  9. #9
    Join Date
    Jul 2000
    Location
    Northern Wisconsin
    Posts
    2,011
    I'd personally go with the Carrier zoning with one system.

    If putting two complete systems in is done for nothing more than to provide for redundancy incase of a failure of one of them, then what happens if the power goes out due to a bad storm and you don't get power back for days? Following the same logic I guess a standby generator for this possible scenerio would be a good idea. What if the frigerator goes out? Have a spare just incase? All I'm saying is that for a small price you could go out and buy a half dozen electric heaters to keep around just incase your heat goes down and for some reason it can't be fixed within a couple of days. If the air conditioning goes down a nice day or two stay at a hotel with a pool would be a cheap option to purchasing two systems to be maintained.

    Just my opinion.
    Use the biggest hammer you like, pounding a square peg into a round hole does not equal a proper fit.

  10. #10
    Join Date
    Jun 2008
    Location
    va
    Posts
    800
    I'd stick with the 2 seperate systems. Better control of the house and cheaper to operate. Why fire up the monster 5 ton unit to cool off a 1 of 4 zones? While the rest goes out the relief dampers? You run one system on one floor without running the other.....well you know since you already have that setup. The 2 smaller units combined current is probably lower than the 5 ton unit itself. If one system fails and/or needs replacing, it's cheaper to replace than the one 5 ton. My 2 cents

  11. #11
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,058
    Some of what you said would hold true on some zoning systems.

    The Infinity, doesn't use a bypass or dump zone.

    Its a modulating zoning system.
    Contractor locator map

    How-to-apply-for-Professional

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

  12. #12
    Join Date
    Mar 2003
    Location
    PA/DE area
    Posts
    1,535
    Carrier 5 ton 3400 sq ft home with ARZEL and 4 zones sweet. I had to use existing ductwork and I have seamless comfort. I keep the PRICNESS wing at 76 and the SWEATY KING at 72 and first floor and basement zone are at 72ish without running.
    It's NOT the BRAND,it's the company that installs it!!!!!

  13. #13
    Join Date
    Jul 2008
    Location
    New Jersey
    Posts
    24
    This is all good advice and I thank everyone that replied. I don't think it would be cost effective to replace everything with 2 new systems, even though I would like the redundancy. This is why I asked about the 2 different compressor technologies regarding durability. Not only is it now more important that it stays online, I'll also be using the compressor for heat too. I have some concern about wearing out the compressor making heat. After all, I can make heat several way; I can only make cool with the air conditioner. But I remember the old days when my dad used to run the air conditioner in his car once in a while in the winter just to keep things lubricated. My car now has an automatic climate control system where the compressor clicks in and out year 'round, and after 168,000 miles and 13 years, it still works great. So my justification for a heat pump is it will last longer because it used more. I am going to get quotes on either the top of the line Lennox or Carrier hybrid systems. Thanks to "beenthere" for schooling me on a reciprocating compressor. I had an idea how a scroll worked. If there is a thread debating between the 2 types, I'd be interested if someone could steer me there. Thanks again.

Page 1 of 4 1234 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