Chiller help

Is there a better way for the "makeup" water system? If one has a small leak that remains undetected, one could have zero glycol and 100% water [my situation].

After doing a little exploration for the salt water pump, instead of using a 3400 RPM pump with a 2.5" impeller in a 3.5" housing [which just doesn't sound efficient] I went with a 1800 RPM pump with a 5" impeller. It was a little more $$, but should run much quieter [it's under the deck of the main salon], and last longer. The discharge volume is the same. The AC guys seem to have a problem supplying the chill water pump, so I'm exploring using the same manufacturer of the SW pump for the CW pump, with the proper flow, of course!

Here's the comparison between the proper sized trunk line for my boat [using 1" copper, not the plastic garbage], and what boat builder used, 22mm. And one must remember, when the trunk line was "T connected", as well as unions, they had to put inserts, which further restricted the flow, to make the connection. Beyond comprehension!!!!

I'm doing a whole system change-out. AHU's, CW pump, Chiller, Trunk lines, valves & T's. They said the SW pump was fine with a 2.5" impeller instead of the 3" that was in it. However, it was discovered that the pump was leaking, so I was faced with a re-build or replace. I chose replace. The "dead" one was a 2 year old [Sept 2016] Scot, so I was looking for a longer lasting pump.

The answer is: I've assessed my usage of the vessel in the last 3 years. Number of guests aboard at any one time was 3, for a day cruise around Central FL. Intended usage is to loop with current girl friend. Space available for the chillers is small, very-very-very small [look at post #35], and trying to work on one would require many labour hours to remove access ports on mid-ship berth, and possibly remove one of the two units to work on the other. Having had one repair job for a sensor was sufficient to convince me.
If the AC fails, I'll moor the boat, fly home until it's fixed. It's not a charter vessel, it's a floating RV!! And in an RV, if the AC stops working, use the "Two-Sixty" model - Roll down two windows and go 60 mph!! LOL I've lived on ships for half my life - and sometimes the AC went kaput. So long as I have beer in the fridge, and the ice maker is producing, I'm good. Captain Bligh said it best: A true sailor can sleep in an oven, or on a cake of ice!! LOL

As I learn about the system, I also have learned about the maintenance habits of the vessel's two prior owners [most likely their captains, though]. I'll admit to being ignorant of some system maintenance - education does come at some cost - and as a deck officer, I didn't get play with the engineering systems on the ships. But, one of the owners [captain's] opened up the make-up water supply valve on the AC system before I bought the boat. . . sigh. Doom on me!

Another example of the prior owners' [or captain] maintenance. When I purchased the boat in 2016, the water maker had 3 hours on it [Date of installation is unknown]. In 2018, when I was transiting in the LANT, I started it up. Of course it wasn't working properly. But when the tech came out to trouble shoot, and "educate" me, we discovered that the three pre-filters had no filter element in the containers!!! Now what idiot would take filter elements out, and not replace them??? Sigh!!

At the end of the day, some stuff just isn't "surveyed" at the buyers survey. But if there IS a next time, I know what & where to look!! Yachting is so much fun, and educational too. But I did pick a bad year to stop drinking!! LOL

Christmas in April. . . New Chiller has arrived - 48K BTU variable with titanium coils!! And 6 new air handlers.

Now the real work begins. A real-life lego set for sure!! Lot's of tight little spaces in the boat to work with.

at needs a little jewelry. You know: BLING

Groco valves & unions with some hex nipples for good measure. . . Just mapping out the "how" and "where".

Now "they" did get one hose "right" on the original installation from the manufacturer; a 25mm lead. The requirement is for 1", so I'd accept the mm equivalent of .984252 as "close enough".




But whatever "good" was done with the 25mm, it was "undone" by stepping down to 5/8" through the reducing ball valve.



that had some ferrous metal in it, and hose barb connection that further reduced the flow!! Dometic wants to see 3/4" FULL FLOW to the AHU's in the new application.

And remember, this installation is not increasing the factory original 48K BTU AC unit, nor are the AHU's being increased.

The chill-water pipes on the AHU's are 1/2". Dometic want's to see 3/4" supply going as close to the AHU as possible before reduction. . . Yeah, 5/8" is close. I get it. But it is still "under-spec". And the whole system was configured with "under sized" piping.

Salt water pump set up, with the 12" rise as required by Dometic. The original installation had the discharge coming out horizontally right into the SW supply line.


Same thing on the chill water pump package; 12" vertical rise. The original installation had the discharge coming out at the top, but no rise; just a 90 degree elbow.



The installer is now setting up the copper lines and making connections. I just might have AC running by 04 June. It's been an arduous process.