We are in a condo development built in 1970's, and are now facing the changeover from "freon" to puron a/c units. We have run into problems because our current units run through 1/4 inch lines into the condos. The new puron units "require" 3/8 inch lines (or so we have been told.) Our existing chases into the units will not accommodate the 3/8 inch lines so some of the new puron units are being connected to the existing 1/4 inch lines. They seem to be working, but we have heard that this may 1) invalidate the warrenty, 2) reduce the efficiency below 13 seer, 3) cannot be done (even though it has been done), etc. What is the real story? What happens if this is done, vs. the problems it may cause down the road? Thanks for your help.

We are in a condo development built in 1970's, and are now facing the changeover from "freon" to puron a/c units. We have run into problems because our current units run through 1/4 inch lines into the condos. The new puron units "require" 3/8 inch lines (or so we have been told.) Our existing chases into the units will not accommodate the 3/8 inch lines so some of the new puron units are being connected to the existing 1/4 inch lines. They seem to be working, but we have heard that this may 1) invalidate the warrenty, 2) reduce the efficiency below 13 seer, 3) cannot be done (even though it has been done), etc. What is the real story? What happens if this is done, vs. the problems it may cause down the road? Thanks for your help.

The real story is that

The unit has to be installed to the manufacturers specifications contained in the install manual.

If Puron R-410A is replacing a R-22 the lines have to be flushed by a special flushing agent. The new refrigerant uses a different oil for compressor lubrication and the old oil must be removed since it is not compatable with the new oil.

All joints have to be brazed to with stand the higher operating pressures of R-410.

The inside coil (Evaporator coil) must be replaced to match the new outside unit since the R-410A refrigerant operates at a higher pressure, the newer coils are larger and the old smaller original coils will NOT allow operation at 13SEER due to not being designed for the new refrigerant.

There are more items but I thought I would just post a few since I believe you will have a problem in the future with your new unit unless it is installed correctly as per the written manufactures instructions.

The system may work but not as designed or intended and yes this setup can void the warrenty since the install instructions are not being followed.

Please see attached.

Hi, Thanks for your quick response. Given the above info, does it make a difference if the air conditioner is a "straight cool". Are there some companies ie: York, that can be effectively hooked up through a 1/4 inch line without causing the problems you mentioned?
Thanks again.

Given the above info, does it make a difference if the air conditioner is a "straight cool".

Given the info it has a determental effect on strait A/C or heat pump units.

Are there some companies ie: York, that can be effectively hooked up through a 1/4 inch line without causing the problems you mentioned?

The unit being hooked up has to be installed according to the manufactures install instructions. If in doupt call the factory but I already know the answer and I have given it to you..

Puron is a trade name for Carriers refrigerant so I believe we were talking about Carrier. York has basically the same set of rules but you can check with York factory for your answer.

One other item you did not mention but special care needs to be take with is line length. There are also rules in the install instructions which require larger tubing over extended lengths or heights. It is all in the factory install manual or if you wish call the factory.

We have run into problems because our current units run through 1/4 inch lines into the condos.

I have never found a structure that the correct line size could not be run. I have found some HVAC dealers that have said that so they did not have to do the extra labor to run the new lines. I have also found homeowner associations that did not want new lines because of esthetics since they would have to be boxed in.

I just tell it like it is.

I would be concerned about head pressure if you ignore the factory specs and hook the system into too small of a line. The high head pressure can, and most likely, lead to premature compressor failure.

As previously posted you will have to replace the evap coil or at the very least install a TXV.

Thanks for your help.