T&T: "the best" AC system?

[Ron Rogers]

Marine Air and Cruiseair are both subsidiaries (acquisitions) of the Dometic 
Corporation (Italian refrigeration folks - big time.) I have two Cruiseair 
units (12,000 and 16,000 BTUs) and they have demonstrated two things to me. 
First, it is essential to use large diameter ducting with a minimum number 
of turns. Second are two interrelated facts: you must have a thermostat in 
each area served and a A/C unit in each area served.

The pilothouse, in theory, is going to be the hottest location with the 
saloon next. They can be served by the same compressor unit, but there will 
be some temperature differential depending upon drapes and blinds, etc. The 
digital control should be in the pilothouse. How hot does it get there? 
18,000 BTU could well be adequate for the combined load of the pilothouse 
and saloon.

However, the stateroom and adjacent spaces below require a separate unit and 
digital control where you sleep. I cannot guess what is required below, but 
certainly at least 12,000 BTUs. One rule is to never buy too big a unit as 
this will cause the control and the unit to cycle too often and at least 
wear out the control and maybe the compressor.

Find out the temperature extremes in your area - both the Bay and the Delta. 
Figure out whether you need a reverse cycle unit. Include in your data 
collection the size of your generator.

Now, call KK and ask them what the used in their KK42s both East and West 
Coast. Obviously an A/C for the PNW would be inadequate for the East Coast, 
etc. Go with what they recommend and try to get a blueprint with the ducting 
delineated so that you get good distribution - this is key.

Another benefit of A/C is dehumidification. The installer is key. Are there 
many yards and individuals installing A/Cs in the Delta? If so, skill trumps 
brand every time! In addition to Cruiseair and Marine Air there is Mermaid - 
a very good brand sold through Defender and others. Do you have the time and 
skill to do this yourself? The Mermaid Company supports DIY. The raw water 
pump or pumps (either is feasible) MUST be properly installed and the raw 
water filtered by large Grocco filters. These pumps are not self-priming. 
You can minimize thru-hulls by using one large raw water pump for both A/C 
units. BTW, ducting will be easier with a dedicated unit below.

Ron Rogers

----- Original Message ----- 
From: "badornato" <adornato at gmail.com>


| am about to bite the bullet and put an AC system in my KK42.  although we
| never need it in san francisco, we spend a fair time with the boat up in 
the
| Sacramento Delta area where it gets over 100 degrees frequently enough to 
warrant relief. The local AC guy recommends a marine air (dometic) self 
contained turbo vector 18,000 btu unit we can put in the pilothouse bunk and 
vent over the staircase between lower master and salon.
| any experience out there with this unit?