T&T: AIR CO: CENTRAL CHILLING SYSTEM VS STAND-ALONE UNITS

[Steve Sipe]

Pascal Gademer wrote:
> what size boat ?
>
> i was under the impression that chilled water system were only practical on 
> larger boats... 60, 70 + range ?
>   
<snip>
While boat searching, we looked at a Hans Christian Independence 45 that 
had a chilled water system installed. There were 4 zones with zone valve 
controls, with reverse cycle (heat pump). It seems to me that although 
it's a pretty deluxe system, the overall impression is one of overkill. 
(On that particular boat, the installation looked like it was completed 
by a 1st year apprentice. Pretty ugly.) I would agree that the chilled 
water system is better suited for a larger boat. We saw a Hampton at the 
Annapolis show that had multiple chillers, and 3 phase to boot! Marine 
Airr units, phase inverters, a field repair nightmare! But it was a 
pretty impressive installation. Very cool!

With multiple units whether they be self-contained or splits, I consider 
the inherent redundancy of multiple units to be a considerable plus; if 
one goes down, you still have an area that's conditioned, you may be 
able to cannibalize one system to keep the other running. We experienced 
this very scenario bringing our current boat home after we took 
delivery. The 3 ton primary unit toasted its compressor contactor. We 
were still able to run the unit in the cabins at night to sleep. With a 
single chiller, the same scenario would have put the whole shebang out 
of business.

Although I don't have direct experience with the Mermaid line, I *do* 
have lots of background with Marine Airr & their proprietary (read 
$350.00) control boards. They're nearly impossible to do any sort of 
"work-around" with, and require an OEM replacement (read higher cost, 
difficult to obtain). The Mermaid uses generic controls and can be made 
to run in a variety of options if the need arises. For a cruising boat, 
that just makes a whole lot of sense. Not everyone can fly their service 
guy in to the boat with a compliment of service parts in hand if the A/C 
goes down!

If I were to replace our current system, I'd be tempted to do a chilled 
water system, simply because I can & it would be cool, but I'd bet I'd 
end up with multiple self contained units, probably Mermaids. <G>

My 2 cents.

Steve Sipe