My mom's 22 year old 4 Ton 10-seer Carrier A/C condenser is shot. Her furnace is relatively new.She wants to replace the old unt with a new Puron Carrier 4 ton condenser.One HVAC company is saying that they do not install new evaporator coils because it is unnecessary, and the efficiency will be around 12 or 13 if the old coils are used with a 15 seer unit. They say they have never had a problem with leaving the old evaporator coils in.Another HVAC company is saying that it is important to install new coils because the efficency won't be good, and also the unit will be under more stress with the old coils and will likely only last for 4 years.Which of the two is correct?Thanks,J.

Neither of them are correct. The coils *MUST* be replaced when switching to R-410a(Puron). R-410a and R-22 are not compatable at all, nor are the oils, and R-410a operates at much higher pressures than R-22....yet another reason to change the coils. BTW, did you know that the manufacturers will *NOT* stand behind their warranties if a correctly matched coil is not used with the new condenser??I would suggest that you get a properly matched system from and have it installed by a *COMPETENT*, licensed, insured, professionally trained HVAC technician. and don't walk, but run away from those two companies. Don't forget to get that 10 year parts and labor extended warranty with the new correctly matched system. Also demand a copy of the ARI Certificate of Performance for the new system. If they can't or won't give you one, then show them the door.FWIW, I would not put Carrier in my home on a bet.

Katy-West Houston Air had written this in response to :Mixing R-22 and R410A is serious invitation for trouble. Once Mineraloilmixes with the Polyolester oil you can just about guarantee compressorfailure after compressor failure. Using the old lineset is OK, but theyMUST be flushed with RX-11, and no chinching. We use a minimum of 1 canper system after an inital high pressure nitrogen purge to insure all ofthe old oil is stripped from the lines. We then follow up with a secondhigh pressure dry nitrogen purge to help remove any RX-11 liquid that maybe present in the lines and provide about a 2 hour vacuum to the system.-------------------------------------KJPRO wrote:##-----------------------------------------------##Delivered via Construction and Maintenance ForumWeband RSS access to your favorite newsgroup - alt.hvac, - messages and counting!##-----------------------------------------------##

New Evaporator Coils necessary for new Condenser ?

May 06, 2008 21 Replies

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KJPRO 18 years ago

Using an older coil is for the Hacks, like Stormy. You don't use a old R22 coil for a new R410 system, PERIOD!!!!!

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Katy-West Houston Air 17 years ago

Katy-West Houston Air had written this in response to

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Mix> "Stormin Mormon"

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