Hi guys
Looking for some advice, After years of AC installations with iccassional fridge work I am now doing a lot more fridge work , predominantly cold stores, display cabinets , blast chillers etc,
This has made me realise there are some things that I learnt back in college 16 years ago that has long been erased from my memory and I'm trying to make a massive effort to become an expert in these things

I am starting with subcooling and wondered if you guys could recommend a good book, YouTube channel, or website that is English and uses celcious rather than Fahrenheit (it just confuses me sometimes they don't say which measurement they are using)

And while I'm here maybe you guys could help me with afew questions
1. If no details are on the name plate of the condensor is there a rule of thumb for the target subcooling in celcious? And does this Vary with different refrigerants and different types of equipment i.e. Air con, cold stores, chillers , freezers etc

2. What would you guys aim to get the sub cooling to on a condensor for a fridge cold store with an exp valve and a 40 +metre pipe run? Would you stick to the rule of thumb or would you make adjustments to compensate the long run?

3 when measuring with a temp probe for the subcooling so you place your probe immediately after the condensor?, at the liquid line service port, or somewhere else ?

Really appreciate any responses
Thanks in advance