Carver Owners Forum

I have a 1999 350 mariner needing a A/c refit. Stock unit is 16,500btu unit mounted under the front dash. It seems to be way undersized. I noticed the newer 360's moved to at least a 20k unit. Has anyone done an upgrade that they were satisfied with? I really don't want to have to do this twice..haha


Thanks Bobby

Bigger may be better! Do your research I'm sure no matter which way you go other then replacing with same exact unit your going to have to retrofit.

If you go to a higher capacity unit you most likely will have to modify the duct work to allow for the additional airflow or your coil will freeze up.

cstraubs wrote:Source of the post I have a 1999 350 mariner needing a A/c refit. Stock unit is 16,500btu unit mounted under the front dash. It seems to be way undersized. I noticed the newer 360's moved to at least a 20k unit. Has anyone done an upgrade that they were satisfied with? I really don't want to have to do this twice..haha


Thanks Bobby

There was an option for a second smaller unit mounted under the salon seating by the galley I believe in some years, that could be a possibility......actually in ours the system works quite well ( read meat locker), have you checked and cleaned all of the return air filter screens that are behind the grills, once plugged they will greatly reduce the air flow......

Welcome aboard Bobby.
It may not be as simple as swapping out with a larger unit. As mentioned above, you may need to move more air. Check the specs on the larger unit first. Also, bigger isn't always better, there's a science to calculating the size of a unit for a given space so you don't have too small a unit running all the time and not doing anything, or too large a unit that will short cycle all the time. The space/volume to cool down/heat up, ambient temps, etc. need to be considered.

Why are you replacing it? Is it that it's simply not cooling enough? If so, there are things you should check first that affect performance before going through the expense of replacement/upgrading. Your particular conditions such as your location and whether you're in an open slip will also have a bearing on whether a bigger unit is required.

Another issue with bigger is that it will cool the air quicker, but because cooling is short cycling, it is not removing enough moisture. Thus you have a low temp but high humidity.

If you are going to replace, I'd start with a brand new unit of the same size, and then add a second smaller unit (5k btu?) in a convenient place, if in fact the original size was undersized.

Another thought, if you have checked all external areas for any blockage, condenser, filter, general air flow around unit and all is good, you may want to consider descaling the internal parts of the unit before replacement.

I suggest you replace the unit with a newer more efficient unit. One thinks just fill the freon because it is low however things have improved considerably and they do produce much cooler air. The coil may be reaching it's lifespan and the blower motor also not to mention the electronics. You replace one thing and then another eventually goes. Been there done that.

The best option out there is a new MarinAire not to be confused with Marine Air. I replaced a 16,000 btu Marine Air with a 14,000 btu MarinAire in my previous 32' express. The difference was night and day. The new unit would freeze you out if you wished not to mention they use Toshiba compressors which are dead quiet. I kid you not, you can stare the unit in the face while it is on and wait for the click of the compressor relay and you still cannot tell it is running. Quiet a few over at BOC went this route and could not be happier with the results. I also plan on upgrading the Marine Air units on my Carver in the near future, especially the one under the bed which is noisy and produces some rather small but annoying vibration.

The quality of the unit is very apparent, stainless steel pan, insulated blower and compressor, built in diagnostic gauges and the list goes on.

If you need trouble shooting/assistance, they answer right away and know exactly what they are talking about. Here is a link to the 16,000 btu MarinAire unit and you will like the price. http://www.marinaire.com/Marine-air-con ... ba16k2.htm

waybomb wrote:Source of the post Another issue with bigger is that it will cool the air quicker, but because cooling is short cycling, it is not removing enough moisture. Thus you have a low temp but high humidity.

If you are going to replace, I'd start with a brand new unit of the same size, and then add a second smaller unit (5k btu?) in a convenient place, if in fact the original size was undersized.

+1 on this. A friend of mine updscaled his boat to a bigger unit and ended up with cold... wet air. not very nice at all.

Fraser