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Are same SEER heatpumps equivalent efficiency if they are communicating vs non-communicating?

mattlope | Posted in General Questions on

Are heat pumps of the same SEER rating basically the same efficiency if they are:
– communicating (AHU and condenser connected via proprietary thermostat) vs non-communicating (condenser responds to line pressure differences)?
– actual variable speed (infinite speed variations) vs multiple stage (more than 2 stage) variable speed?

I am trying to make a final decision on a heat pump and wonder if anyone has any insight.  I am not really looking for any design advice (I believe I have that all figured out) just insight from anyone that has experience with the following equipment.

I am in the panhandle of Florida been building my home for a while and is ICF exterior walls with spray foam on the hip roof decking into the soffits, so it is a very well sealed and insulated house.  I have a properly sized range hood w/ respective make-up air system, whole house dehumidifier, and ERV.

I already have a Manual J, S, & D complete, the duct design complete, etc. and have been taking a hard look at the following 3-ton units (pricing includes install of equipment and commissioning – I will be doing the duct work).

– 18 seer Bryant/Carrier – [288BNV036 / FE4ANF005 / KFCEH2901N09 / SYSTXBBECC01-B] – $11,750.00 (provided by local HVAC contractor)
  – 10 year registered parts warranty and 1 year workmanship warranty

– 20 seer Coleman/York – [HC20B3621S / AVV38CE221 / S1-6HK06501006 / S1-THXU430W] – $11,625.00 (provided by local HVAC contractor)
  – 10 year registered parts and labor warranty and 1 year workmanship warranty

– 20 seer Bosch BOVA-36HDN1-M20G / BVA-36WN1-M20 – $7,000.00 (ordered online and installed/commissioned by independent HVAC contractor – pricing does not include refrigerant, typical install consumables, etc.)
10 year defects in workmanship and materials warranty and labor charges associated with the repair or replacement of the part ninety (90) days from the Commencement Date

And so I know the Bryant and Coleman are communicating units so a bit more complicated of an install (and servicing) and will be stuck with the proprietary thermostats, but both the AHU’s and condensers are true variable speed from what I understand.  So these units would run constantly at the lowest speed to maintain maximum efficiency, which would help with fresh air delivery and circulation, dehumidifying, air filtering.  These units are available from the same HVAC contractor who seems to have an excellent rating, has been responsive, and says repair parts are readily available if servicing is needed.

The Bosch is not communicating and does not seem to be a true variable speed.  This makes the install much more traditional and I can use third party thermostats if I want.  The HVAC friends and acquaintances that I have discussed the Boschs with absolutely love them.  They are easy to work on and maintain.  Basically all diagnostics can be done without gauges and testing equipment.  I am not positive on how readily available repair parts are.

The Bosch is Energy Star rated so there are some possible rebates to offset pricing (I understand new construction doesn’t necessarily qualify).  The Bryant is not Energy Star.  It is unclear if the specific Coleman setup is Energy Star.

I am leaning toward the Coleman mainly for the SEER rating and the 10-labor warranty.  As it was explained to me, if a condenser needs replacing, this warranty covers everything, including the refrigerant.  The warranty just seems amazing considering how many times my friend’s and family’s entire heat pumps have been replaced and major components repaired over the years.  However I can’t find many reviews for these units.

But the Bosch’s SEER rating, simplicity, pricing, ability to diagnose problems directly on the board without a tech etc. is also very appealing.  And has quite a few decent reviews.  The warranty isn’t great, but the money saved initially can be considered for repairs if not expected to be excessive.

The Bryant is supposed to be an awesome machine and has some good reviews (other than for the thermostat) but with the slightly lower SEER and no labor warranty, I am not so sure it is the best value.

All that being said, do any of you have any insight between high SEER units that are communicating vs non-communicating?  Do they provide the constant airflow?  Which is more efficient?  With the same SEER rating, are they equally efficient?  They all seem to use inverters to vary the voltage/energy consumed, correct?

Thanks for any feedback…

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  1. walta100 | | #1

    My list of must have features for a modern heat pump.
    1 Variable speed compressor.
    2 Electronic expansion valves for both heating and cooling.
    3 ECM indoor blower motor.
    4 Communicating thermostat.

    The communicating thermostat is a faster and easier install generally 4 wires non communicating can be up to 15 wires.

    I don’t think the brand matters much at all. I think the installer is the secret sauce. If you pick a good installer, he will pick a good brand to sell so you don’t have to think about it.

    The brands in your bids seem to exclude the big players and I have to wounder if that is choice you made.

    I understand every house in FL has the HVAC equipment and duct work in the attic but under stand it is not a code requirement and pretty much a dumb idea. Consider going ductless or making room in the conditioned space for the HVAC. The biggest advantage would be that for third the price of the spray foam you could cover the attic floor with R60 of cheap fluffy insulation reducing the surface area of your thermal envelope by 20% or so.

    Consider one of the ducted mini splits.


    1. mattlope | | #2

      I really appreciate the response.

      The brands are what is locally available and easily serviceable for this area with the contractors that have above average ratings (and actually return emails / calls and show up). The Bryant is a Carrier and the Coleman is a York/Johnson Controls.

      The attic is a conditioned space , the spray foam was installed in 2017, so the ductwork and AHU won’t be exposed to a hot attic. My ERV and dehumidifier will be using the ductwork as well so I do need it. But I do appreciate the ideas.

      I’ll have to verify the presence of the electronic expansion joints, but I’m definitely leaning toward communicating.

      Thanks again for the insight.

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