I have mostly been working on residential air conditioning. Due to a shortage of techs here in my town I have found myself making the transition into walk-in refrigerators and freezers. I am not really too concerned about the electrical as I am the refrigerant charging.

I know superheat and subcooling. Do most of these walk-ins come with TXV's? If so, will I use 10 - 15 degree subcooling on walk-ins as I have in the past with comfort cooling?

Will I be using superheat? What are the biggest differences from walk-ins and comfort cooling with regard to refrigerant charging?