Let's Complain About Air Conditioners

glthomas

Well-known member
Joined
Aug 6, 2012
Messages
49
Fluid Motion Model
C-24 C SE
Hull Identification Number
FMLT2112H213
Vessel Name
Gus
I have a 2013 R21EC with the 110 Dometic 3500 btu A/C and Dometic inverter running off two group 24 Centennial DC24MF batteries in parallel.
Aint worth a flip with outside temperatures reaching over 85 degrees.
If the cabin temperature is above 80 the inverter kicks out on high temp before the A/C can get a good start on cooling the cabin enough to run the inverter.

The batteries supplied by the factory are not amp hour rated to run long the A/C long enough to overnight.

The battery charger is too small at 20 amps to keep up with the amp draw of the A/C when plugged in to a Marina outlet.

While cruising the alternator will keep up and you have A/C until mid day when the A/C won't cool enough to run the inverter. Testing with a infrared the A/C out put air is about 10 degrees lower than cabin temp. In 95 degree Texas heat, you can forget it, the inverter overheats.

What's a Tugger supposed to do?
Does Ranger make a system that can cool as well as Ford truck 12v system?

I'm either going to upgrade my system or upgrade to a larger tug if they make a system that works.
Looks like 4 golf cart batteries with two in series then the two series banks in parallel would give enough amp hours to run overnight. Installing a fan to blow on the inverter may keep it cool enough.
After all that I wonder if the A/C unit is large enough to cool me down in the fist place.
Yes, I want it keep my cabin at least down to 76 degrees when it's in the 90's outside.

I am very disappointed. Can you tell? -🙂
 
We were instructed on our R-27 delivery last summer that we had to have 120 volts AC supplied by generator or shore power to run a/c unit.

I'll attest that it works good, even in Fl or Ga humidity.

I sort of think a locomotive sized battery may provide enough amp hours to use inverter to power the a/c.

I've been told by some not to run the tiny microwave from inverter, but i've used it to power 4 cup coffee maker just fine.

Good luck,
Bill
Blue Merle
R-27
 
Thanks for letting us know about your R21. The first step in this is to contact the dealer you purchased the vessel from so we can work together to make your system work the way you want it to. The way we install that system on the 21 is not intended to be run at the dock. It is only intended for underway use. I make this very clear anytime someone asks me about air conditioning in the R21. Comparing a 25,27 or any of the larger boats is hard to do because they are all straight 120volt powered and using generators to push them and shore power while at the dock. Lets try and work together with your dealer and see how we can make it better.

Welcome to call me on my cell if you need.

Andrew Custis
253-230-0727
 
I also have a 2013 Ranger 21EC with A/C and I live in south east Florida were we get many days above 90 degrees. I have run the A/C at the dock for short periods of time but have never tried to run it over night because we don't sleep over on the boat much and when we do we would not be pick a hot summer night.

Underway we have found that the A/C will work well and get the cabin into the temp. range you require. To help reduce the green house effect in the cabin we have used a windshield reflector from the dollar store and cut it to fit the three upward facing hatches. The material is held in place by the screens and appears to reduce cabin temp. by several degrees. Since the cabin is quite bright and allows great vision in all directions the loss of light through the hatches has not been missed. Since our boat is in the water full time and not covered we have seen a noticeable difference in cabin temp. regardless of the time of year when first opening the cabin.

While the A/C is an expensive option the cost difference between battery power and having a generator running underway is an upside to we and an acceptable tradeoff to me.

Phil Rudin
 
The 12 volt MarvAir system in our 21EC was not designed to be used in hot weather. We don't need to run an A/C system while underway. We wanted a system to keep us comfortable on a windless 85 degree humid night in Florida! We do stay out several nights at a time and most of the time away from a marina. We decided to scrap the 12 volt system in favor of a 110 volt, 8000 BTU unit that can run off either shore power or a generator. Staying one night in a beautiful secluded but bug infested hot sticky location takes away the cost factor when you sleep in COOL COMFORT!

Cool CaptnKarl
 
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