58 ft. Jamestowner, going to put an A/C unit on it. Would like your thoughts what to do or not to do, also size recommended, also not opposed to a regular window mount if youu have thoughts on doing it this way. Primary thought is for dock use, have yet to get a generator, so after I get some of the accessories done Ill best know what it takes to run the the accesorary's. stove & frig like new on propane

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"Come OOON Back............

Two 13,000 BTU should do it if your in Ky.

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OLD HOUSEBOATER

I'd put in a roof mount before I'd go with the window units. Camping World usually has the best prices on roof mount A/C. it is really hard to have a "neat" installation of a window unit on a boat, plus the window unit makes the boat easier to break in.

I just had the joy of replacing one of my two units this past weekend so I am a virtual cornucopia of info on the subject. I replaced a Coleman that was supposedly installed new in 2002. It had no heating element and had given me trouble for some time. My guess was low coolant level but try getting someone to come out to a boat for any reasonable price and you quickly learn that your money is better spent toward a replacement. I went to a local RV supply place in Chattanooga and paid $556 including tax for a Dometic Duo-Therm with a heating element. The hardest thing about replacing one is getting help to take the old unit down two decks and over the rail and getting the new one up. You need three men so one can climb ahead while the other two pass off one end and so forth. Your biggest problem will be cutting that hole in the roof. I would guess that most houseboats are designed to have that hole centered from side to side and you can generally look inside at the ceiling to see where the joists are to get your fore and aft location. Beware that the manufacturer may have run wiring for lights down the center so cut carefully. Those wires if there can stay there as the unit can be installed around them. Now to power your unit you will need dedicated wires of proper size going to a dedicated breaker. How do you get them fished through without tearing out the ceiling? Simple I hope. You will sacrifice one of those existing light wires to pull your new wires through. I suggest using the ground wire. Now tie four wires to the breaker end of that old ground wire. One positive, one negative and two grounds because you are replacing the ground wire you are using as a pull wire. Once you have a hole and wires the rest is simple. Make sure the new unit has a roof gasket included. Good luck.

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The Judge Rules


Edited: 07/23/2007 at 10:05:30 AM by TheJudge

Hello Judge, i understand your frustration at not being able to get service on your rooftop AC unit, but i have some insite on why this is so. Having done HVAC work for the last 26 years in both residential and commerical i can state that these units are nothing but glorified window units and since they have no gauge ports, parts are difficult to impossible to get, and you are paying between $65.00 to $95.00/hr for a tech to check the unit out(plus travel time) most customers have heart failure when they get the bill.(espically when a new unit is under $600.00 and are very easy to install) But one thing i have found over the years is that half of all issues are from dirty coils or filters. most people never check these or look at the coils.(remember the condenser coil is a blow thru which means the coil can only be inspected for dirt by removing the cover). If you get 10 years out of one of these you are better of just replacing the unit, esppically since the new dometic 15,000 btu units draw less amps than there 15 year old 12,000 btu units.



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UC FANS
1999, 52' Monticello - Miller Tyme
Port of Aurora IN

Millertyme, you are dead on as to why they cannot service those things without charging a fortune. Some guy told me he would have to solder in a fitting just to test the unit and be able to recharge. I could easily see $250 plus for repair so I opted for replacement. By the way, I did remove the entire old unit and cleaned it thoroughly. It was filthy and it did allow me to get another half season out of it but all things have a wearout point and I was worn out whether the unit was or not. I also figured the newer ones have to be more efficient though the guy that sold it to me said they had not changed the technology much in the last 15 years.

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The Judge Rules

This is my first A/C season for my Harbor Master with two Duo-Therm units. The Brisk-Air units seemed to work well when I would first turn them on, but would begin to cycle quickly and never cooled the boat adequately. After much study and the scratching of various parts of my body, I found that the thermostat sensor on both units was tucked away against the cold air duct in the 'shipping position'. After moving the sensor into the return air path per the installation manual, both units began to work great. It had obviously been installed improperly and had remained that way through 20 years and at least 3 owners!

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Harbor Master 47
Watts Bar Lake - TN River

On the Brisk-Air A/C's, I have found the heat elements are just about worthless. I have 2 on my boat, replaced one of the A/C units when I bought my boat 7 years ago. The heat part is only good for about 45 degree weather and is pulling 12 1/2 amps all the time. Have found that a good quartz heater on 1/2 power warms as good and that only pulls about 6 or 6 1/2 amps. If you put them on full power it warms the boat easily to 32 and some below. The old Intertherm A/C I had on the 36 Gibson I used to have was much better as far as heat went. I don't think they make them anymore though.
Not saying the Dometic is not a good A/C because I think it is, just the heat part is lacking.
When installing a Dometic A/C, if the distance between the roof and the ceiling is as much as it is on a Gibson you will need to make up a sheet metal spacer to connect the air box of the upper unit to the ceiling unit. They won't quite reach each other out if the box.

Edited: 07/16/2007 at 06:35:31 AM by gibson44

You are also right about the roof spacing on a Gibson requiring some spacer connection between the top and bottom of the air supply. Because I use Van Pans under my units that makes the problem even greater. I just used duct tape to tie the two together. Do not spare the tape as you want it to be a good connection that will not pucker and split.

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The Judge Rules

Hey Millertyme, I have the original air/heat roof unit in my 1978 CarlCraft 37.  The blower will cut out when it gets hot (after about 5-10mins).  If you shut it down for ten mins, she'll blow ice cold again till she warms.  Over and over.  If you can give me any info from my description, that would be great. By the way, it's a: INTERTHERM  model# SCH15.5AH.
Other numbers near were: 77nv14r1  APPLIANCE# A000126015.  Thanks for your time.

Edited: 07/17/2007 at 08:10:14 PM by RCPILOT

Sounds like your problem is just a worn out fan motor. Get all the numbers of of the fan motor itself and call WW Grainger, or take the fan motor to them. more than Likely they will have a replacement at minimal cost.

Thanks Houseboat, thinking about it, that sounds pretty logical. I'll take it out this weekend and try to get one next week. I'll let you know what happens. Thanks for the info.

Edited: 07/19/2007 at 11:58:35 PM by RCPILOT