Man from trane...
yes it is (txv).
yes the recommend the approach method.
Just wanting to understand "Subcool".
Back to my issue, while the tech was adjusting psi's he did repeatedly take LLT to compare via the aproach method. Thru the range of system psi [(65-180) / (70-250)] the aproach differnece went from a high of 8 to a low of 6. Lennox recommends 11. the tech was at a loss to explain this.