" wrote in message
news:RT0Uj.2965$5_1.654@trndny05...
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.

http://www.consumerreports.org/cro/a...-205/overview/