Ask Me Help Desk - Upgrading an ac

We have two separate AC units. They are both 10 seer with 1/2" pipe. The pipes are in the concrete foundation with marble 16" tiles on top of that.
It is a long distance from the outside units to the handlers inside the house. One is 2 Ton, the other is 3.5 Ton. They are 20 years old.
We would like to upgrade to 16 seer. Several companies have told us that a 16 seer can not work with a 1/2" pipe. They say they would have to chip up the foundation to install larger pipes. this is impossible as we would have to then replace the foundation and marble floors . Is there any way we can upgrade to the 16 seer with the existing 1/2" pipe?
Any truthful information would really help.
Thanks...

We have two seperate AC units. They are both 10 seer with 1/2" pipe. The pipes are in the concrete foundation with marble 16" tiles on top of that.
It is a long distance from the outside units to the handlers inside the house. One is 2 Ton, the other is 3.5 Ton. They are 20 years old.
We would like to upgrade to 16 seer. Several companies have told us that a 16 seer can not work with a 1/2" pipe. They say they would have to chip up the foundation to install larger pipes. this is impossible as we would have to then replace the foundation and marble floors . Is there any way we can upgrade to the 16 seer with the existing 1/2" pipe?
Any truthful information would really help.
Thanks.................................

To start with you probably have 5/8 OD pipe since OD sizes are used in refrigeration and A/C systems. Depending upon the distance you will have to use 3/4OD OR 7/8OD copper pipe on newer units. I know of no way around this issue since the larger diameter return lines are needed by the compressor in the unit. IF these sizes of pipe are not changed to what is called for in the install manual for your new units you will more than likely have compressor failure and since the pipe size was not increased the warranty will not be honored by the manufacturer.

I have been in your shoes before on this subject with one of my customers years ago and I ended up routing the lines differently so I would not have to destroy the interior of that customers home. Get with your HVAC company and see if there is another route they can take with the larger lines to help alleviate this problem but whatever you do make sure to use the larger size copper pipe because you will not be able to get the efficiency you are paying for let alone the good possibility of compressor/system failures and lack of warranty.

They should be able to go up the outside, through the attic and then back town.

Quote:

Originally Posted by ma0641

They should be able to go up the outside, through the attic and then back town.

We are in Florida and have no attic. Plus we are in a hurricane prone zone.
Code will not permit on roof pipes. I know you said use the attic, but we are open beam throughout the entire house.
We are at a loss as to what to do. We want to upgrade to more efficient units but is appears we have hit a brick wall.
Thanks for your reply.

Are the air handlers in a closet that goes to the ceiling? How about a hollow beam across the ceiling and run the piping through that.

No hollow beams. They are all solid wood. The handlers are in closets. On on each side of the house. However the closets go up to the beam ceilings and there is no way of hiding them.
Thanks again.

Ouch. Doesn't sound like you have to many options. Is there any path you could take to run the lineset and then have a carpenter "box" it in. Boxing can actually add aesthetic value to a home when done correctly. Where there is a will, there is a way. I would suggest having a few different hvac companies come in and get their take on things. See which one suites you best. Good luck, and please let us know what they come up with.

Quote:

Originally Posted by mygirlsdad77

Ouch. Doesnt sound like you have to many options. Is there any path you could take to run the lineset and then have a carpenter "box" it in. Boxing can actually add asthetic value to a home when done correctly. Where there is a will, there is a way. I would suggest having a few different hvac companies come in and get their take on things. See which one suites you best. Good luck, and please let us know what they come up with.

Thanks for your impute. So far we have had 3 companies come out and all have different ideas. It is a real dilemma.
Thanks

Quote:

Originally Posted by hvac1000

We have two seperate AC units. They are both 10 seer with 1/2" pipe. The pipes are in the concrete foundation with marble 16" tiles on top of that.
It is a long distance from the outside units to the handlers inside the house. One is 2 Ton, the other is 3.5 Ton. They are 20 years old.
We would like to upgrade to 16 seer. Several companies have told us that a 16 seer can not work with a 1/2" pipe. They say they would have to chip up the foundation to install larger pipes. this is impossible as we would have to then replace the foundation and marble floors . Is there any way we can upgrade to the 16 seer with the existing 1/2" pipe?
Any truthful information would really help.
Thanks.................................

To start with you probably have 5/8 OD pipe since OD sizes are used in refrigeration and A/C systems. Depending upon the distance you will have to use 3/4OD OR 7/8OD copper pipe on newer units. I know of no way around this issue since the larger diameter return lines are needed by the compressor in the unit. IF these sizes of pipe are not changed to what is called for in the install manual for your new units you will more than likely have compressor failure and since the pipe size was not increased the warranty will not be honored by the manufacturer.

I have been in your shoes before on this subject with one of my customers years ago and I ended up routing the lines differently so I would not have to destroy the interior of that customers home. Get with your HVAC company and see if there is another route they can take with the larger lines to help alleviate this problem but whatever you do make sure to use the larger size copper pipe because you will not be able to get the efficiency you are paying for let alone the good possibility of compressor/system failures and lack of warranty.

Thanks so much for your information. We have been told the same thing by one company that came out. We were hoping there was some little secret that could utilize the pipes we have. Maybe some sort of valve that would reduce the amount of gas to accomidate the 5/8 but I assume that would defeat the purpose and as you said cause compressor failure.
Thanks again.