Do I really need new copper pipes for a new AC?

Question

I am getting a new AC (Lennox XC13) and of course it is built for R410A . I have existing copper line but it's size left the sales guy stating that I need to replace the copper and make it bigger. Evidently 3/4 is too small and would make the new Lennox work less efficient. Does anyone know if I am being hosed?

Answer 1

different refrigerants/units use different sized tubing. i doubt if you are getting hosed. for the amount you are spending, it's not that big a deal. just tell them you want to keep the old copper. then you can scrap it. if he were ripping you off, he would have discussed new ducts and other bs.

however, while everything is apart, i would consider looking at the ducts for the best possible airflow/insulation etc. i really doubt you are being "hosed".

Answer 2

You are not hosed by the sales representative, you must comply to manufacturer's specification. Lennox will not shoulder any responsibility  if something goes wrong with your AC unit. Let the Lennox authorized installer to handle the installation for warranty reason.

Answer 3

this sounds right, and if it's a different refrigerant, it needs a different oil, so no contamination takes place. replacing all the lines is a good idea. keep the pipe and get the money yourself, it's like 2.80 a pound!

Answer 4

Yes you absolutly need new lines.  The oils in the diffrent refridgerents are not compatable with each other.  Even though you can buy products to try and clean the linesets this is left only for a very last resort.  

Lastly your new AC system is probably a TXV metered system where as your old system was a fixed orfice system.  Lineset sizing is very importent in making sure your unit works properly and stays working properly.   Its not just for efficency, it maintains the balance in the system.  

For example.  The refridgenent will exit the outdoor system compressed and in liquid state.  It will then enter the coil and all that coldness gets absorbed by the heat in the house.  It then leaves the coil in a vapor state which is safe for the compressor to recive.  If the balance, pressure, or efficency of the system is set wrong, you could end up with liquid getting back the compressor causing a hydrolock (damaging) or a frozen coil causing damage to the furnace or handler below it.   This is why a Hvac tech has so many gauges and tools to properly set up Ac systems.  

Im in the feild and to not change the line set would be a foolish practice.  Just one peice of forign matter left over from the old ac system could cause damage to your new system.  Its not worth it.

Answer 5

Hi you old a/c was a R22 system which operate at 250 psi to 300psi on 70 to 95 f  day your new a/c with R410A operate @ between 470psi to 570psi on the high side of the system which your old copper pipe would not handle

Answer 6

it seem right

Answer 7

Depends on the distance.  I would expect that the old piping would be adequate, but as a fraction of the total cost, it's down in the noise.  Check with another local vendor for more advice.

Answer 8

I would have It Changed. Old system was probably R-22 Freon. as you say new 1 is R410a it Runs at Higher Pressures.

Answer 9

you need to look at the manufactures specifications.

Its not surprisings that you may need to change you lines for new equipment with new freon.  you should have your own installation guide along with your users guide.  in the install paper work it will note what is required.

Answer 10

yes he is telling you the truth

Answer 11

hes right you lose efficiency with the wrong size copper what id be concerned about is lennox i work on them and they always need worked on