No

The temperature oudside has nothing to do with what you keep the indoor
temperature. Normally the temperature should be between 16 to 20
degrees colder at the supply register than at the return grille. But
that depends on indoor humidity, return temperature and air flow. Many
service techs can't do capacity and efficiency testing, I doubt that
you can.

I do it for our local utility on occasion. It takes several hours and
I use about six thousand dollars worth of test equipment.

Stretch