lineset sizing over 50ft

[machman25]

I am currently getting quotes for new heat pumps the air handler for the second floor located in the attic is about 55ft from outside unit.I'm told that current line size is too small-1/2&3/8 but because appox. half of the lineset is inside the wall they tell me it will do and that they will increase from the current 1-1/2 ton to a 2ton 13seer unit to make up for lost eff. is this correct or should the line be replaced?

[comfortdoc]

Replace the lineset and use the unit size necessary for the heat load. Is there a way the existing lineset can be abandoned in the wall and new one run exposed on the outside inside a Linehide cover?

[amickracing]

Sounds like you need a second opinion (in person, not via the net). But since you're here :-)

If there is any way you can swap the line set out with minimal damage to the house, do it. If you can't, do everything you can to find a new way to run the lineset, maybe even change the location of the out door unit.

There's a chance you'd never have problems, but if you do you'll regret not doing it correctly the 1st time.

Not quite sure about upsizing the unit to make up for lost efficiency... sounds like a major bandaid for something that should simply be done right to begin with.

[machman25]

I would rather not go outside in this case.If no other choice I would open up walls. Is this a must do and what problems could I have if line is used as is?

[captainrat]

PMI per manufacturers instructions, not what someone says is right ! be carefull
outside the wall i fine & can be covered with a device that looks like a gutter

[machman25]

thanks for the replies