Ola is me again, thought Id jus ask another dumb question.
In words only can you describe how to find head pressure using design condenser temperature, ambient air temp and a comparitor.
The handout i have says to:
Find design condenser temp
add 30F (17C) to the ambient air temp
read across comparitor to apporpriate refrigerant to find pressure. (but where did the 30F (17C) from? was it the condenser temp?)