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Replacing central air with heat pump - different opinions, which is "right"?

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  • Replacing central air with heat pump - different opinions, which is "right"?

    A little background - located in PA, 1950's cape cod, roughly between 1,800-2,000 square feet total conditioned space, ~1,135 of this is downstairs, upstairs is VERY warm in the summer and AC (1 zone) is hardly keeping up with it up there today (84 degrees outside at 11:20am, AC has been running since this morning and it went up from 68-71, and actually is now going up even more (72)... Going to be in the 90's next couple of days We have a 10 month old otherwise we wouldn't be so quick to want to fix this, downstairs feels fine. Service provider states there is a leak and they can't find it. Outdoor compressor was installed in 2000. Air handler apparently replaced July 2009 (the 4th contractor to come in pointed this out, no one else seemed to notice - not even our service provider??? We have been here since Nov 2009). Obviously this was not disclosed during the home sale. It is a 2 ton system, Rheem. One large air return at top of stairs to second floor (in the knee wall). 2 bedrooms and one bathroom upstairs. Bathroom does not have a vent, no windows. Want a heat pump so we can reduce the oil bills. Service provider recommended replacing the system, so we have 4 estimates.

    1st estimate (our service provider) - 2 ton Amana 13 SEER heat pump (1 stage) OR 14/15 SEER heat pump (2 stage). $585 price difference. Model info not listed. Add two high returns upstairs and one low return downstairs (requires cutting into the hardwood floor ). Only contractor to say we need more returns. Did not think at the time to ask about adding a vent to bathroom upstairs (since oil is the back up so if the heat pump is on, we would like heat to get there!). Prices only good for 10 days (seems like a pushy gimmick to me). I think we have pretty much crossed them off the list.

    2nd estimate - We are leaning towards this one. Premium Amana HE heat pump 15 SEER, 30,000 BTU, 2.5 ton (currently we have a 2 ton system). Don't know if it is 1 or 2 stage, not sure what model this is b/c it does not state it on the estimate. Will ask for clarification when I get a moment today. No mention of needing more returns. I asked and they took a look at current return and said it is plenty big enough. The rest of the contractors also said the same. Asked about adding vent to bathroom and said they would run a new duct (6" supply).

    3rd estimate - A talker. "Pushy" but in a nice way, if that makes any sense. Clearly states model/details of both compressor and air handler. Left brochures. Everrest (Goodman with a different name slapped on?) model ASZC160241 2 – TON , 16 seer , two stage compressor , two speed condenser fan motor , R-410A refrigerant , outdoor Heat pump Unit. Everest model AVPTC, model 2.5-3 ton, variable speed air handler and coil (different tons between air handler and compressor??). 4" supply run to bathroom split off from an existing duct upstairs that feeds a bedroom. Lifetime unit replacement on compressor only, makes me wonder if it's the same for the other estimates too? No mention of there being a difference in warranty between compressor/air handler with other estimates. Also says we have to have a service contract, 1st year free, for the 10yr parts/labor warranty, or at least that is how I am reading it from the estimate. Probably won't go with them.

    4th estimate - Also provided model/details in estimate. OPTION 1: Amana 2.0 TON ASZC16 -17 SEER 2 stage heat pump condenser, Amana 2.0 ton air handler (priciest out of all estimates), 1 stage OR OPTION 2: Amana 2.0 TON ASZ14 - 15 SEER - heat pump condenser, Amana 2.0 ton air handler, 2 stage. $1,755 price difference. Would also split off a duct to feed to bathroom.

    So my main questions are:
    1. Do we really need more returns?
    2. Is upgrading from 2 to 2.5 tons a waste of money? The price for the 15 SEER 2.5 ton system is cheaper than the 16-17 SEER 2 ton system by $1,610, but will it be more expensive to run? Will the cooling issues upstairs be solved with either option?
    3. Should 1 stage vs. 2 stage be a factor in our decision? I'm assuming this has an impact on the SEER rating.
    4. Should a new duct be run to the bathroom upstairs (would come from the basement where the air handler is) or is it OK to split off an existing that is already up there?
    5. Anything that is gimmicky/unnecessary about what is being proposed by anyone?

    TIA - baby is waking up from a nice long nap so I have to go!

  • #2
    Wow! A lot of questions! First off, let me say that it will be hard to properly diagnose and recommend a new system without first seeing your existing house and system. With that in mind, let me make a few comments:
    1. Any new system can only be properly designed and selected after a Manual J calculation of the heat loads on the residence. Manual J calculations take into consideration such things as the home's insulation, type of windows, weatherstripping, expected outdoor temperatures, indoor design temperatures, etc. Many HVAC service companies can provide this service, but usually do not because of the extra time involved in collecting data. They rely on the TLAR (That Looks About Right) method of design.
    2. Rheem equipment is some of the best available. Properly set up and charged it will provide good service. Why didn't you get a bid from a Rheem dealer?
    3. Although you have expressed some urgency in getting this done, I think that you have the time to do the calculations to design this properly.
    4. Keep in mind that if the current 2 Ton Rheem unit does not properly cool the house, a new 2 Ton unit (no matter what the SEER) will not cool any better. Tonnage is equal to thermal capacity. SEER is the energy efficiency of the unit. A new 16 SEER 2 Ton unit will not cool any better than an old 12 SEER 2 Ton unit; however, it will be cheaper to operate.
    5. Make sure that the condensing unit, evaporator, and air handler all operate as a matched set.
    6. Excellent idea to get several bids.


    In answer to your questions:
    1. Do we really need more returns? Maybe, Manual J will give you good advice.
    2. Is upgrading from 2 to 2.5 tons a waste of money? From your description of the situation, it would seem reasonable that the current system does not have enough capacity. Manual J can provide the answers here. The price for the 15 SEER 2.5 ton system is cheaper than the 16-17 SEER 2 ton system by $1,610, but will it be more expensive to run? The higher the SEER, the lower the cost to run the system, but don't get sucked in by all this. It will take a while to pay back those extra costs. Will the cooling issues upstairs be solved with either option? Don't know. Depends on design of system. Again, don't confuse capacity (Tonnage) with eficiency (SEER).
    3. Should 1 stage vs. 2 stage be a factor in our decision? To get the higher SEER, it usually takes a multi-stage system; however, a 2 stage system will be more complex than a 1 stage system and therefore more expensive in first costs as well as ongoing maintenance costs. I'm assuming this has an impact on the SEER rating. Usually.
    4. Should a new duct be run to the bathroom upstairs (would come from the basement where the air handler is) or is it OK to split off an existing that is already up there? Manual J can help here. Depends on existing duct sizes and air flow requirements.
    5. Anything that is gimmicky/unnecessary about what is being proposed by anyone? Yes, the requirement for a maintenance contract in order to provide a warranty is a gimmick.

    I wish you the best of luck with this. Take your time and do it right - it's an expensive proposition and you will have to live with it for a long time.

    Let me know if you have any more questions, and keep us advised of what you do.

    Comment


    • #3
      Wow thanks!

      Yeah I was a little confused that everyone who came in didn't take a look at the rooms etc. and do some sort of calculation. We are scheduling a couple more estimates and keeping our fingers crossed that the system doesn't crap out completely.

      Not really any Rheem dealers around here. We are staying away from the company that originally installed the system - was going to call them but they seem rather rude in their responses to poor reviews on Angie's list (plus there are poor reviews on Angie's list!). I mean even if the customer was rating them poorly for reasons not totally in their control, one would still expect some level of professionalism in the responses. Also, if they are the ones that replaced the air handler without replacing the condenser at the same time, isn't that the wrong solution?

      The system cooled fine until this season. I mean last summer is somewhat of a daze between being incredibly pregnant and then caring for a newborn, but I think I would remember it being hot up there! Especially since we have been here a few years. Anyway, I was leaning towards 2.5 tons over 2 tons, but then I remember that the 2 ton system seemed to be cooling just fine in the past. I worry that paying for more tons is not totally necessary for the size of the house. But then no one took measurements!

      Thank you for your input!

      Comment


      • #4
        "Also, if they are the ones that replaced the air handler without replacing the condenser at the same time, isn't that the wrong solution?" Not necessarily.

        "I worry that paying for more tons is not totally necessary for the size of the house. But then no one took measurements!" You're on the right track.

        Find a company that will do a Manual J design. Don't fudge any of the numbers. You will get the right answer.

        There are also other design booklets: Manual S for equipment selection. Manual D for duct design. Manual T for vent and register layout.

        Suggest you Google Manual J to learn a little about it.

        Comment

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