Aircon pump

[ian w]

I am not getting enough water through the system to keep the aircon going on my 53
When going above the current March 1000 gps what pump is best in the 1500 gps range

 

[carolinacoast]

I would call Depco pump in Clearwater FL.

 

[Pascal]

I m using a 1620GPH March TE-5.5-md for 72k BTU

Stick to march. Oberdorfer, Cruisair, Scott dont last as long and suffer from impeller and housing erosion with time

I get mines from https://flagshipmarine.com/pumps/

I ve used them on the boat I run, last ones I got was for a back up water maker and zero speed stab cooling. Great service and prices.

 

[ian w]

Another question
Although l had a diver down cleaning the thu hulls the seacock was closed
I should have left it open in case something is growing inside it .Does this sound logical

 

[racclarkson@gmail.com]

Also using TE-5.5 for 4 condensing units. March pumps wear like any pump. You can test this by removing the pump end (leave back half attached to motor) and adding a very thin copper or teflon washer to the ceramic washer that should already be there. In the alternative, you can replace what's there with one washer of slightly greater thickness. This will force the impeller forward or backwards (can't remember which) and bring flow back to specs. I did this and got stern thruster flow. Motivation to find a quick fix enhanced in summer. Ordered a new pump end 5-6 years ago and it's still in the box.

Consider descaling raw water loop for possible obstructions. I've filled sea strainer with Bromine tabs for years and there is no growth in the baskets. Won't stop grass, but will stop barnacles completely.

 

[Pascal]

Another question
Although l had a diver down cleaning the thu hulls the seacock was closed
I should have left it open in case something is growing inside it .Does this sound logical

Shouldn’t make a difference

 

[PJT]

What size through hull?

Mine is 3/4 and some recommended increasing it to 1” to 1 1/4”.

Thoughts?

 

[racclarkson@gmail.com]

Mine is 1-1/4"

 

[ian w]

Mine is three quarter Used to work fine

 

[PJT]

What size through hull?

Mine is 3/4 and some recommended increasing it to 1” to 1 1/4”.

Thoughts?

Reason I ask is my pump in take is 1”, can 3/4 “ through hull supply enough flow?

I’m still learning!’

 

[Boatsb]

Pump capacity is directly related to the btu rating of the system. Bigger is not better. It's just bigger.

Before armchair mechanics send you down the wrong path get the numbers and run the math.

 

[Captain Ralph]

It's all in how fast you want the water flow thru the sea-cock, strainer and to the pump.
All of our AC inlets are 1", 1" strainers, and 1" to the pump.
Never an issue.
Oh, short lengths also.

I remember 20+ years ago watching clamp-on Amp meters while choking down sea-cocks. Pump motor tries to spin the same RPM as amps went up.
I observed; Less drag, less current drawn,,, less heat.

What you have is usually what you have to live with,, less out of the water modifications. The factory had deals with so much of what the mfg supplied and what would just work.

Just think; what makes my equipment's life easier...
Not a thought when the boat was built.

Now, With this in mind, the actual thru put of an AC pump still has constraints. 180 to 200 GPH per every (ton) 12Kbtu.
The water needs to flow correctly thru the condensing coils; not to fast, not to slow to transfer the thermal, correctly to the water.

So, easy draw, correct flow is the game for AC units, IMO..

 

[PJT]

Captain Ralph

Perfectly Stated!

Thank You!

PT

 

[ian w]

It appears that my new Ocean Breeze unit for the saloon requires a lot more water than the original Cruisair

 

[ian w]

I should have said the original Cruisair only lasted 37 years

 

[Pascal]

On a related topic, today I came back to the boat after the system was off for 11 days while we were out of town. Turned on the pump breaker, checked the discharge… almost nothing. I had to back flush the hoses between the manifold, coils and discharge with pressure to clear a whole colony of small mussel shells blocking everything.

 

[racclarkson@gmail.com]

On a related topic, today I came back to the boat after the system was off for 11 days while we were out of town. Turned on the pump breaker, checked the discharge… almost nothing. I had to back flush the hoses between the manifold, coils and discharge with pressure to clear a whole colony of small mussel shells blocking everything.

Bromine