What effect does refrigerant type have on tube diameter selection?
Small diameter tubes are more desirable as operating pressures increase. Higher pressures typically are required to condense new refrigerants (e.g., R410a or R744) compared to refrigerants that being phased out (e.g., R22). Working pressure is directly proportional to wall thickness and inversely proportional to diameter. In other words, for tubes with the same thickness, smaller diameter tubes can withstand higher pressures than larger diameter tubes.
