ac unit

How large is your RV? Is it ducted? 110*? You'll be lucky to get any RV AC unit to cool it down to 85*. It's cooling down now, so, you have another 6 months to consider your options.

40 ft ducted air yes cooling now have to replace a leaking capacitor unit kept blowing the beaker after 30 min of running.yes i have time

A new unit might use a little less power, but btu's are btu's.

If you went to a minisplit unit more cooling may be available but it almost certainly will be expensive.

15-20 degree heat removal temperature differential is a typical design criteria for any residential AC unit.

Are you getting 20 degrees differential between the air-in and the air-out?
Have you checked the plenum divider is well placed and sealed properly in the lower section?
Have you ever been topside to remove the cover and clean the coils?
Are you parked broadside to the afternoon sun? Shade?

Generally an older 15KBTU will move the same heat out as a new 15KBTU A/C unit.

Yes you probably need a second cooling unit.

15-20 is about it no matter what cooling unit you have.

40 ft unit? HOW many roof airs do you have? Towable or Motorhome? You need a MINIMUM of 2 AC's to cool a 40 foot. Better to have 3. Doug

hoffy wrote:
will a brand new ac unit out perform a 12 year old unit as far as cooling or is a ac unit only capable of lowering the temperature 15-20 degrees old or new? my old unit is a 15k btu coleman and doesn't cool my living room in 110 deg temps although i think the rig needs 2 units in the living room.

thanks

Well first: a brand new one may outperform in terms of how much electricity it eats. but delta R of 20 is generally considered good.

thanks all i guess its all i get with my current set up!