Sail4beer

Air conditioning

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Looking to install an a/c unit in a Catalina 42 this month and was wondering who like what and why. 
 

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I’ve installed a few Dometic Turbo self contained units in customer’s boats. Very easy install and the customers were happy very happy with them. 

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I’ll keep an eye on this thread.
I have a 16000 btu Mermaid of unknown vintage (guessing about 15 years old; I’ve had the boat for 10) that probably needs replacement. 2 years ago it wasn’t cooling and local HVAC shop that seems to be the go-to for marine systems took it out, sent it to Mermaid and new compressor installed.  I paid Mermaid direct for compressor and freight. (internal short was diagnosis)

Worked in A/C mode last season, but heat mode didn’t work well at end of season. Hasn’t seemed to cool well this season. Had HVAC folks look at it a month ago, they diagnosed stuck reversing valve and got it to pump heat and cycle back to cool. They were going to check refrigerant level but found caps on ports were glued on. Not sure with what as applying heat did not break them free. 

I would NOT recommend Mermaid. Less to do with reliability as I recognize unit is up there in age. Not sure why they would seal service ports other than to require another round trip between WI and FL that is neither cheap nor convenient. Mermaid wouldn’t talk to me and both the service tech and owner of the business said they were kind of rude and condescending to them. 

I think ballpark estimate for new unit installed was around $3K. Forget what brands they handle but I’ll try to remember to look it up tomorrow. 

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I'll be keeping an eye also.

IIRC Dometic and Marine Air are the same units and parts.  Which I think really only leaves Webasto.  Good units from them too.  But, I find Marine Air to be the most common in boats I look at.

Curious to know if you will run it dockside only or if you have a genset,  If yes on the gen, what did you fit?

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8 hours ago, Hitchhiker said:

I'll be keeping an eye also.

IIRC Dometic and Marine Air are the same units and parts.  Which I think really only leaves Webasto.  Good units from them too.  But, I find Marine Air to be the most common in boats I look at.

Curious to know if you will run it dockside only or if you have a genset,  If yes on the gen, what did you fit?

Depends on the output of the generator and load requirements of the appliances you are running off of it. 

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The boat doesn’t have a generator. It will be a liveaboard at a marina with shore power.

I have 2 marine air units and a Fisher Panda generator on my boat. I’m looking towards the Dometic turbo like Will suggested.

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The previous owner of our boat installed a Flagship Marine FM18R. My understanding was the build quality was on the higher end, size on the smaller end and generally uses less wattage than comparable. My only two complaints is it doesn't seem to have a dedicated dehu mode and I don't love the rather large controller.

It cools our 42' boat well. 

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The HVAC shop I use handles Cruisair.  Which was purchased by Dometic a number of years ago.  I guess they finally retired the Cruisair name.  As pointed out, Marine Air is also under Dometic ownership.  

There is another company, FL based, with very similar name called MarinAire.  Don't know anything about them other than from their web page.  Seem to be relatively new (2007).

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I did see the Cruisair 18,000 as well. I just found suitable space under the nav station seat Aft with a deep well under it near the keel sump to drill a through hull water intake and condensate drain. On my 42, the a/c unit is under the forward bulkhead seat with space to spare, but his model has the forward house battery in that location and has no other place to re-locate.

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2 hours ago, VWAP said:

IMG_3897_small.jpg

This is my dad’s setup on his J/27 (yes you read that correctly)

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On 8/10/2020 at 5:13 PM, Sail4beer said:

Looking to install an a/c unit in a Catalina 42 this month and was wondering who like what and why. 
 

We have a Flagship Marine FM18 (might be wrong about the letters, but 18k btu). It works well and seemed to be compact and efficient. Previous owner put it in and we haven't used it in a year. Only complaints are the size of the control panel - it's like a 10" diameter, and the condensate collection and pump is in an inconvenient place, which I think may be an installation choice.

 

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I replaced an older Marineair unit with a 16,000 BTU Webasto unit.  Has worked well though the unit sometimes (I can't predict when) runs substantially past the thermostat setting.  Any advice there is appreciated.  Webasto has recommended moving the temperature sensor to focus on the return air but I haven't seen much improvement with that approach. 

One note - Webasto stresses switching the heating / cooling reversing valve every month to keep it lubricated and functional.  Even in the summer, I try to move the system to heat mode briefly on occasion and then switch back after a few minutes.  Same but opposite in cooler months. 

 

 

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I installed 16000 Btu/h Self-Contained of Marineaire to replace a Dometic 16k unit in my 1989 Carver. The installation was pretty easy with all parts except the air splitter being a direct fit. The unit cools very well and is quieter than the original, it also draws less power and is 10-15 pounds lighter. A great money saving retrofit that's highly recommended for older yacht owners.

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Thanks, I installed that unit and it works well- cools the whole boat!

I still can’t figure out your wife and daughters names...

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On 8/10/2020 at 5:13 PM, Sail4beer said:

Looking to install an a/c unit in a Catalina 42 this month and was wondering who like what and why. 
 

A/C equals condensation 

like a mini water maker 

think of this when locating and installing the system 

Stagnant bilge water  and  mildew from a poorly , installed , located   AC makes the boat stink like a British pub carpet

ac uses plenty of seawater for cooling 

choose an oversized sea strainer 

if possible discharge the cooling water on the side of the boat , bootstripe ....away from the dock 

on many boats this means port side 

discharge on the dockside  is noisy when magnified by the dock 

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I had a Cruisair on my Hinckley, and have dual units on Restive. No probs with either.No gensets, they run of shore power. Interestingly, they will also run off the alternator, as we proved on particularly brutal afternoon, where it made supper tolerable. Sun went down, turn it off.

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Frigomar do a great inverter system. No startup surge so you can minimise genny surge, or maximise shore power without tripping. You can also turn it down if shore power is having trouble or you are on a different dock. Won awards at METS the other year.

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The companionway window unit setup is popular with racers who want to keep their boats cool and dry inside, but be able to take the weight off the boat when they are racing. Another option is thru the forward hatch, which is more out of the way.

Self contained units are good retrofit, but having the compressor in the cabin is noisy. having a split unit you can put the compressor in the bilge or cockpit locker somewhere. 

Make sure you mount the pump and inlet well below the water line. I was on a boat where the pump would lose prime every time we went sailing and heeled the boat over. So we either had to remember to close the thru-hull or re-prime the pump when we got back to the dock.

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The Marineaire fit on a marine plywood base under the settee as with my own boat and I was able to line up the port side bootstripe for the water discharge. There wasn’t much room for error. 
I used a welder’s hammer to screw it into the hull since it was such a good fit.

The air handler disconnects so the unit can fit in a tight space. The only problem I had was that the air handler wouldn’t spin once I wired the unit and powered it up the first time. I had to remove it and disassemble the blower housing to straighten the fan-which looks like a hamster wheel- it was off balance and rubbing against the inside of the housing. I got it centered and spinning freely, re-installed and it fired up properly, ran quietly and cooled the boat from 88 to 72 in a few minutes. 

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I had a Cruisair stowaway turbo (16000 BTUs) go bad after many years of good service. Was considering purchasing one of the newer Dometics, but have heard quality of their units has reduced in recent years.

I was between choosing a Webasto FCF and a CTM unit, and decided on the CTM. Buddy of mine installed one early this year, and is content with it. Low price point, solid looking unit, good replacement option for cruisair (I was able to use the same SMXir control from my cruisair). https://citimarinestore.com/en/ctm-marine-air-conditioners/11908-ctm-ct16-16000-btu-marine-air-conditioner-115v-24101c.html

I like the titanium coils. My cruisair's compressor actually failed because of a hole in the rusted condensing coil.

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On 12/15/2020 at 10:25 AM, ryley said:

You might look at Phil's website

 

https://boatrx.com/how-it-works/

I studied that option before buying the CTM. However, with the CTM I added a soft start from micro air and the amperage drawn is minimal. My 3.5kw generator starts it without a problem and regular running amperage drawn is no more than 10 amps with 16,000 btu capacity. That small 12 VDC unit is only 7,000 btu and the amperage consumption is pretty high, so I would have had to change my whole battery bank system and the unit itself is over $5,000. Also, I read in other blogs that the control box runs very hot, close to 120 Fahrenheit, have you seen that issue?

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