Replies

1. 
   junkhound | Mar 13, 2006 03:16am | #1

   How old?  P/N?  

   Some of the old stuff is only 70% as good a COP as newer combinations, in which case it would pay to replace the whole thing.  Many utilities give a rebate for new heat pumps also - check that part out in your locale.  Here (PSE) it's 10% rebate of intalled cost, where Mom lives in IL, it's $100 a ton rebate roughly.  

   Whaterver they get make sure it has a scroll compressor (quieter, last longer), preferably a Copeland (no financial interest here, jus' opiniou)

1. 
   Biloxiblues | Mar 13, 2006 03:44am | #3

   Good point JH.  I'll have them check w/ util co.  Rebates might push them to a more efficient new system if a reasonable pay-back can be shown.

2. 
   DanH | Mar 13, 2006 03:33am | #2

   The evap coil ("A coil") in the air handler must be "matched" to the condenser unit. Generally they should both be replaced if one is replaced with a different style. But the evap coil can be replaced without replacing the air handler.

   If ignorance is bliss why aren't more people

   happy?

1. 
   wrudiger | Mar 13, 2006 03:45am | #4

   The new units are more and more designed to use Puron or other freon replacements, and they are not compatible with any older equipment.  (You can still get freon-based systems but they are being phased out.)

   The coil and compressor does't need to be from the same mfg, just designed to work together.  I actually got a 2 SEER boost (from 12 to 14) from a 3rd party coil vs. the one from the manufacturer.

   Between the rebates, reduced operating cost and quieter operation it may well be possible to justify the upgrade to a new system.  If your handle has anything to do with your location (AC running 9 months out of the year) I gotta believe there are savings to be had.

2. 
   Biloxiblues | Mar 13, 2006 03:47am | #5

   Thanks Dan.  Sounds like our a/c guy made a ligit recommendation.  Was just worried he may be pushing new stuff for the sake of new stuff.

3. 
   rjw | Mar 13, 2006 04:10am | #6

   >>The HVAC guy says to replace the whole system.

   There has just been a manufacturing requirement change that became effective this year.

   Replace just part and you've got built in obsolescence.

   Do the whole system.

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4. 
   Tim | Mar 13, 2006 05:32pm | #7

   "..what amount of a systems efficiency is attributable to the condenser and what is to the interior chiller itself..

   You mention "the interior chiller itself", yet some of the subsequent KIA posters are refering to evaporator coils and air handlers. IF your refering to a chiller, and not a split system air conditioner, such as would be installed at your home, then the answer is that if the condenser and evaporator barrel are properly sized, most of the energy and subsequently the efficiency is associated with the compressor and motor, i.e. the "chiller itself".

   IF you are actually talking about a standard split system, the answer is still the compressor/motor, though in this case contained within the condensing unit, is still responsible for the most of the efficiency.

   In either case, replacing a portion of a system is seldom a wise choice. I would recommend that you or your client seek the services of a competent HVAC engineer rather than guessing.