Circulation Pumps

The information below applies only to MSWA brand marine air conditioning units and may not apply to other brands or systems.

For standard installations, each MSWA air conditioning unit requires its own circulation pump. Pump sizing depends on your MSWA unit capacity, installation layout, and plumbing run. Based on what most MSWA customers typically use, the following circulation pump sizes are common:

• MSWA 6,000–9,000 BTU units: most customers choose a 300 GPH circulation pump per unit
  
• MSWA 11,000–16,000 BTU units: most customers choose a 500 GPH circulation pump per unit
  
• MSWA 20,000–24,000 BTU units: most customers choose a 1,000 GPH circulation pump per unit
  

We carry two types of circulation pumps, and the correct choice also depends on where and how the pump is installed:

• Non-submersible pumps for dry, above-bilge installations (such as MarinAire magnetic-drive pumps)
  
• Submersible pumps for bilge installations (such as select March pumps)
  
  (Note: the 1,000 GPH pump is not submersible)
  

Each pump has different head pressure ratings, and factors such as hose length, vertical lift, fittings, and bends all affect flow.

Using one pump for multiple MSWA units

Some installations use a single circulation pump to supply multiple MSWA units. In these cases, the pump must be sized by combining the required flow for each unit, and a pump relay panel is required to ensure proper operation.

Example:

Two MSWA 16K units (500 GPH each) would typically require a 1,000 GPH circulation pump and a compatible pump relay panel.

Proper sizing is critical:

• Undersized pumps may prevent one or more units from operating correctly or keeping up during peak heat
  
• Oversized pumps may require reducers or a ball valve to regulate flow depending on conditions
  

Because shared-pump systems are more dependent on plumbing layout and head pressure, we strongly recommend consulting a qualified marine air conditioning installer to confirm pump sizing and system design.

The main difference is how and where they are installed.

Most March pumps are submersible, meaning they are designed to be installed in the bilge or areas that have high moisture. (note** the TE-5M-MD 1000GPH pump is not submersible)

MarinAire pumps are non-submersible and designed for dry, above-bilge installations such as closets.

Both March and MarinAire pumps are ignition protected and magnetic drive and suitable for marine environments. The correct choice depends on your installation layout, available space, plumbing run, and head pressure requirements.

If you’re unsure which pump is best for your setup, checking the spec sheets of the pumps are recommended.

No. These circulation pumps are designed and intended specifically for marine air conditioning and marine water circulation systems.