Another Air Conditioning Queston

My current 'river' water (as opposed to sea) plumbing setup, has a 1000GPM pump supplying a 7K unit and a 16K unit. The pump was a 1/2" T plumbed to it's output then 1/2" hose going to each unit. The 16K unit is about 3' higher than the 7K unit. So the unit that needs the most flow, must have its water lifted 3' higher. That has been OK, mostly I believe, because the pump is a bit bigger than required, but hardly seems ideal. It seems some sort of flow restriction in the line going to the smaller, lower unit, would balance things better. Perhaps a valve closed slightly might work. That said, I hate unnecessary complexity. The current setup has worked for several years.

What Ye Think??

Sounds very similar to our setup, which came that way from the factory. We have a single pump that services a 12k unit for the Saloon, and a 16k unit for the pilothouse and berth. The smaller 12k unit sits a little higher than the 16k, but the 16k has a much longer hose run. We've never had any issue with the single pump servicing both units. We get good flow from both of the above waterline thruhulls for each unit - looks more like a garden hose in terms of volume, unlike the trickle I see on some boats. I'd say that if it is working, then no need to worry. How does the water flow look?

The current setup has worked for several years.

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Then that's what I think too!

Well, if it ain't broke, don't fix it. But in the spirit of prevention take a look at the thru hull output of both systems- are you getting a good stream of water out of both?


If not, and I would assume that the 16K unit would be getting less flow of course, then this is what I would do: Replace the 1/2" tee with a 3/4 x 1/2" tee with the 1/2" on the branch. Then run new 3/4" tubing all the way to the 16K unit. That will approximately balance the flow.


BTW, it is 1,000 gph not 1000 gpm.


David

djmarchand said:

Well, if it ain't broke, don't fix it. But in the spirit of prevention take a look at the thru hull output of both systems- are you getting a good stream of water out of both?


If not, and I would assume that the 16K unit would be getting less flow of course, then this is what I would do: Replace the 1/2" tee with a 3/4 x 1/2" tee with the 1/2" on the branch. Then run new 3/4" tubing all the way to the 16K unit. That will approximately balance the flow.


BTW, it is 1,000 gph not 1000 gpm.


David

Click to expand...

Thanks, Yes that should be 1000 gph. I know better.

djmarchand said:

Well, if it ain't broke, don't fix it. But in the spirit of prevention take a look at the thru hull output of both systems- are you getting a good stream of water out of both?


If not, and I would assume that the 16K unit would be getting less flow of course, then this is what I would do: Replace the 1/2" tee with a 3/4 x 1/2" tee with the 1/2" on the branch. Then run new 3/4" tubing all the way to the 16K unit. That will approximately balance the flow.


BTW, it is 1,000 gph not 1000 gpm.


David

Click to expand...

Increasing the hose to the 16k unit will increase the flow even after you adapt back to 1/2" at the unit.
Best idea. ?

Have a similar setup supplying 3 12K btu units all at different levels. When replumbing the units I put 3/4" pvc ball valves before each unit. This allows me to match the flows. I use a 5 gallon bucket to measure flow. Simple stick it under the discharge and time how long it takes to fill.

Ted

"plumbing setup, has a 1000GPM pump"

That would be a very large pump, that your main engine probably could not power.

Turn the tee around so the water to the larger unit is a straight flow.

Rather than look at the hose positions look at the outlets. Are they both pushing water well away from the boat in a steady stream?