What size ton a/c unit outside would be used on a 1500 s.q.foot ranch home.

not enough information in your question
for example how many windows , how many rooms will be air conditioned , what is the insulation of the building,
do you want vented ac through the ceiling vents from one ac outside unit or on a wall in a room
how many people will be in the building at any one time
are the windows covered with heavy curtains
is there window tint on the windows
in reality to get the right system , you should be getting quotes from ac specialist installers to work out the mathematics and the correct system to install

The outside unit will work,but not the matching furnace!
you have to have a specific manufactured home furnace, because off Co

If the system is actually doing everything it can, which I do occasionally run into, then it's time to start looking at other factors like the heat loads. Number one problem I run into is either attic insulation or attic ventilation. One thing that really sticks out in your post though is the square footage and tonnage. Now, to be honest, what the square footage is from the home owner to actual living space always varies. Home owners always get the square footage like a realtor, but includes the garage and other unconditioned rooms. What your looking for is the square footage of only the rooms that have a vent. It is 400cfm per ton, 1 cfm per square foot. So if you have a 2.5 ton system, it is capable of doing 1000 square feet of living space. You said 1500 square feet, which would need a 3.5 to 4 ton system. Hope this helps and gets you to cooler days!

There are alot of factors when dealing with this problem. Heat Load ( Typical A/C unit is designed with a split of 20 degrees farenheit.) If you measure the temperature leaving the discharge registers, the temperature should be around 20 degrees colder than the air entering the return air grille (Filter Location). Also your unit seems to be a 3 ton; In which this system is designed for roughly 450 sq. ft. per ton and can go as high as 550 sq. ft. on newer homes with more than adequate insulation values. On older homes with minimual insulation the 400- to 450 sq.ft. rule per ton should be observed. Another reason could be that the units needs servicing like a dirty condenser coil or evaporator coil, improper refrigerant charge, etc can all be issues that can result in your problem.
Finally, most typical units or designed to maintain a home 20-25 degrees below outside temperature. Example 95 degrees outside, inside should not be set lower than 70 to 75 degrees, and the 5 degree range depends on the SEER (Seasonal Energy Efficiency Rating/Ratio ) of your unit. Hope I was helpful in giving you some direction in things to look for to resolve your problem.

HI YOu have a 5 ton unit =60,000 btu=12000 does 500 sqft=2,500 for you no problem.good luck & thanks

You currently own a 2.5 ton AC Unit
500 square feet equals a ton of cooling/ you need a 3.5 ton unit.
If your home is well insulated, good windows and doors and pretty good
shade that covers your house, then I can see a 3ton unit cooling your
house.

Thats another 6,000 btus you do not have and that is a best case for a
energy effcient home.

First off - the 'rule of thumb' is 600' per ton of Air Conditioning. In other words your old unit is a 2 ton unit. So - 2 tons x 600' = 1200'. As you can see if you install the 2.5 ton unit - you will be installing a AC that 'could' cool a 1500 sq ft house (2.5 x 600' =1500 sq ft.). Slightly more than what you need; and the 3.5 ton unit is 'way to big,' (3.5 x 600' = 2100 sq ft.).

Note: fyi - many in the AC business will sometimes refer to tonnage in btu's, i.e. 1 ton = 12000 btu - hence a '2 ton unit' can also be referred to as a 24000 btu unit and vice versa.

So... from the above - you can easily see that "2 tons" of Air conditioning is what is required to cool the 'average' home of 1100 sq ft. "roughly speaking."

Note: it is always best to have a professional 'size' your cooling/heating needs.

One of your questions was could you 'mix tonnage?'

The answer is 'usually you don't mix the tonnage of your outside/inside units.' However, professionals sometimes do (mix the tonnage) in certain situations, and installing a 2.5 ton outside unit with an existing 2 ton inside unit is often done, however, there are some 'tech issues' here and - I would "again" recommend that you call a Service Tech to help you with the sizing/mixing of your cooling/heating needs.

hope this has helped

Here in Florida the old Standard was around 700 S.Foot per ton.
Now days we size them 400-500 S.Foot per ton.
Appears by your Model number you have a 2-1/2 Ton system.
So id give you Max around 1700 SF.
Min 1200 SF depending on the conditions at the home.

Just a thought for you, Most AC companies will give you a free estimate for a new Ac unit, and can tell you what you may need Unit size wise.

Good Luck!

I’m happy to help further over the phone at https://www.6ya.com/expert/michael_341f3f9dee622e54

that is bunch of bull there is always something that can be done. one is the unit big enough for the house? the formula i use is 1 CFM ( cubic foot min)for every SQ foot. basically if your house is 1200 SQ feet you need a 3 ton unite. there other factor, like windows, which way house faces duck size extra. i would get anther guy!

That is a fairly large difference. It is usually ok to have the inside evap. coil and blower up to 1 ton larger than the outside condenser. That will make the unit slightly more efficient as well as less likely to freeze up on low airflow situations. It is not recommended to install a new condenser on an old evap coil. There has been a lot of changes to the design of the coils in the last little while. For example a 10 year old 2 ton coil may only have 3 cubic feet of volume but a new 2 ton coil may have 4 cubit feet of volume.

There are many factors that may have infulenced the decision on what size condenser to install. Many of which can only be done by visiting the home and doing alot of work, checking the duct sizing bioth supply and return, inspecting the insulation and windows of the home etc. etc. Most of the time that never gets done. You can blame the contractor for not doing a complete check, but at the same time you can blame the customer because many contractors that are that good loose the job to a cheaper bid that did not no any of the research. It is a catch 22 for everyone involved.

There is ALOT more to sizing equipment that many people think, sadly that also includes many HVAC contractors. Way too many people use "rule of thumbs" or flat out "guess".

Sorry for the rant but your queston can only be answered by a good well educated HVAC contractor visiting your home. That type of a contractor is getting hard to find these days in such a price competetive world.