HVAC

One pump = 1 head. 2 pumps = 2 heads and so on.

How about some more detail?

What closed system you have? Pump for what media? Do you have a pump already or selecting? What Gpm? What line size? What Vertical Lifts? what running length? What nos of valves & fittings? What Suction length? What what and what what???????????

EEJ, I agree with the above comments. You need to provide more explanation. When you are talking about a pressurization unit, do you mean the water pump, or the expansion tank, or something else?

Two parts!

The cooler must meet the sizing requirements of the tubes for cooling but you cannot fit that unless you know how much of a coverage you have in ft. x pipe size if older system and depends on radiator's sizes?

However if it is an older unit already installed then I would start with the compressor size! That will give you a generall idea of the amount of fluid you are cooling!

And the head pressure will be based on the flow of that fluid that you are cooling in that section of the system!

There are 3 parts:

1. cooler or condenser

2. tubes or evaporator

3. circulating water thru radiators with air flow across them!