Recommended fret sizes for acoustic guitars
 

I had in mind to repair an old acoustic guitar with some issues, like a action that is too high and frets that need to be replaced.
Here and there I found some discussions about refretting, videos, but most of them refers to electric guitars that might need a certain size of frets depending on the player’s needs.

Right now my guitar has frets that are 2.0mm (=0.079inches) wide. I can’t determine the exact height since they’ve been levelled a bit, but that should correspond to a small size.

My question are:
Does the fret height affect the playability on a guitar with high action if they are too low?
What fret size do you recommend?

Low fret height is more difficult to play when it gets to the point where your fretting finger needs to contact the fretboard itself to try to prevent fret buzzing (and on barre chords in general).
Personally I like 0.047" height and width around 0.104 to 0.108" (Evo gold or stainless steel).

Those should correspond to mid jumbo and jumbo, right?

From what I learned, those sizes aren't often used on acoustic guitars, since the strings that you put on them are generally bigger than those of a electric guitar. And that could lead to buzzing, but I suppose, if that happens, that you can file them down a bit to solve the problem.

But I have to prove you right by saying that barre chords are extremely hard to play without one or two strings buzzing. At first I thought it was my problem or the action height (in that case I have to fix it no matter what, maybe I’ll have to replace the whole bridge, but that’s a problem for another time).

The further you have to press the strings down to make contact the more intonation issues become unmanageable, and I believe you end up actually wearing frets faster because of the added pressure.

I like Jescar's 43080 wire for my acoustics when I've done refrets. Very close, or possibly the same, as what's is typical on many guitars these days. It's not especially tall, so you really need to get your action, and possible neck/fb all correct before putting [any] new frets in, unless you want to end up with essentially little improvement.

Tall frets do not cause buzzing, poorly leveled frets (regardless of height) or poor setup (action too low at either bridge or nut) cause buzzing. Fret height is a preference. I personally like taller frets. I have even put jumbos on an acoustic. Taller frets make bending and fretting a little easier. However, if you have a heavy fretting pressure you can get pitchy, notes can go sharp.

I use 0.047" X 0.104" fretwire in both evo gold and stainless. Some retailers call this "medium jumbo", others call it "jumbo". This size keeps your fingertips off the fretboard wood but to me does not feel like running your fingers over railroad tracks. There are taller fretwires sold also called "jumbo" but they are too tall for my preferences.

There is no buzzing issue with taller frets - if anything the opposite.

Many acoustic guitars do ship with smaller fretwire. For example Collings uses
0.043"h X 0.87"w, however many players prefer larger sized wire.

Yes and no. A good sampling of standard fret wires can be found here: https://www.lmii.com/35-fretwire. Note that the difference between the shortest (.035") and the tallest (.057") is .018" (about 1/64"). So, going from the tallest fret wire to the shortest will make the action seem .018" higher.

"Refined" players will notice the difference, many will likely not. If possible, the action, at both nut and saddle, should be altered to suit the new fret height.

I recommend whatever you prefer, what feels best to you. I like short (.035"), narrow frets. Just because that's what I prefer doesn't mean that you will.

Thanks everyone for your suggestions.
I’ll try a bigger size and see how it goes. I wanted to replace them with steel ones at first, but since they are harder to pull out, I will go for some nickel-silver ones this times so I can test them out and when it will be time to change them again, I’ll replace them with the ones made of steel.