Air Conditioning - Is correct Vapor and Liquid line important?

I had a new 2 ton Rheem central a/c installed two years ago. The manual calls for 7/8" O.D. Copper Vapor line and 3/8" O.D. Copper Liquid line. But the old line that is original to the house is 1/2" O.D. Copper Vapor line and 1/4" O.D. Copper Liquid line. The technician simply welded the new line to the old line that is smaller than spec. Will this affect performance of my a/c?

I am asking because the house feels damp the longer the a/c runs. Humidity hovers around 65% at 77 degrees then climbs to 85% if I lower the a/c temp to 70 degrees.

Additional info:
The air handler plows really fast, the manual says there's a low and high speed but I cannot figure out how to lower the fan speed as this may help to extract moisture.

The Vapor line feels cold and has water collecting on it. But it's not as cold as my neighbor's Vapor line.

The evaporator unit is clean, no icing.

Thanks.

How did the system work when it was first installed? Are you sure the suction line is 1/2" od and not 5/8 od?

In years past, a 7/8" suction line would be considered extreme for a 2 ton system. But these days it's commonplace. The manufacturers are trying to squeeze out every last bit of efficiency. I assume we are talking about an r-22 system.

Ideally, a new lineset would be good. But your existing lineset should work at a slightly reduced efficiency.

I think your immediate problem is some other issue. I suggest you have a tech look at it.

I believe you are right that the suction is 5/8" O.D. The system is a Freon system.

I have had a tech guy look at it. After he filled the freon. The high pressure switch kept tripping. So he reduced the freon to where the high pressure switch no long trip.

My tech guy is a professional commercial air conditioner guy. He works fulltime on commercial systems at the local airport. Is that skill transferable to residential systems?

Could it be that when the Freon level got low enough to not trip the high pressure switch, that is not enough Freon to make the a/c as cool it should be to extract moisture from the air?

I read somewhere that you can remove the high pressure switch since it's an option on the Rheem a/c, is that possible?

Something is strange there. If it's a cap tube system then the charge should be by super heat. If it's a TXV then it should be charged by sub cooling. In either case the high side should only be running 20-30 degrees over ambient. If it's higher than that you have either to much gas or a dirty/damaged condenser coil. High pressure switches are usually set about 375 pounds. It would have to be 130 degrees out to trip one on a properly charged and operating system.

The small liquid line could be causing the compressor to struggle & create high head pressure. I suggest replacing the lineset if for no other reason, to keep your warranty valid. As installed, your warranty is not worth the paper upon which it is written.

When the last hurricane blew over the a/c, it put a kink/sharp bend the Vapor line. The tech simply straighten it out but I can see the tube is about half it's original diameter. Could this be the reason why the high pressure switch trips? Because the pressure is being bottle-necked at the kink?

A kink could have serious impact on system performance. You could have done serious damage already. Replace those lines.

Thanks everyone for your contributions. I am having an a/c guy here next week and will show them your responses. I had pointed the kink out to another a/c tech he said it's not a problem because it's still 50% effective. I will make sure he at least cut out the kink and put in a new section in its place.

Your system sounds like it's restricted AND overcharged. The overcharging was probably the result of trying to bring up the suction pressure. The 5/8" suction line in itself is not the main problem. BUT a kinked line of any diameter is. There could be other restrictions as well. It's also possible the lineset kinked inside the wall when the unit blew over.
It's time for a good tech to examine the entire system.

My suggestion is that any time there is a concern about the installation of any equipment the mfrs recommendation should be the final word.

Any knowledgeable refrigeration mechanic can sometimes fine tune these pipe sizing numbers but if you were to call Rheem themselves, not a dealer, I am sure they would offer you some solid advice.

I have yet to find any maker who approved of a bad install.

In fact, here is the contact info for their website:
Rheem Air Conditioning Division • P.O. Box 17010 • Fort Smith, AR 72917-7010 • 479-648-4900

I'm sure if you give them a call and explain your problem they might help.
If they try to pawn you off on a dealer be assertive give them a link to this post. ;)