Ranger 21 EC stock A/C

PHIL RUDIN

Well-known member
Joined
Mar 31, 2012
Messages
47
Fluid Motion Model
C-242 C
Hello to all,

My name is Phil Rudin and I am a first time poster.

We are ordering a 21 EC in the next week and have not been able to find infornation on the 5000 BTU 12V powered A/C unit for the boat. We will be keeping our boat at our dock on the ICW In Lake Park, Florida. This is south-east Fl. where we boat year round and where the weather can get very hot.

The boat will be on shore power year round. If we start the A/C two or three hours before heading out for a run will the A/C keep the boat cool while underway or does the greenhouse effect in the hotter months over come the 12V A/C unit?

Thanks for your input,

Phil Rudin
 
The AC unit is a 12v system, powered by two batteries in the aft storage area. The issues are whether the batteries will hold enough charge throughout your trip and if, 5000 BTU is enough the keep the cabin cool in hot weather. In FL weather I'd expect the AC to put a full load on the batteries.

That cabin is not insulated. 🙁 I doubt the AC will cool it when underway. Hopefully, I'm wrong. I found that cabin to be very hot; I had my R21EC in North GA. I never used the AC, with the temp I experienced, I doubted that 10,000 BTU, much less 5000 would do the job.

I had 5000 BTU AC units in an Albin 27 AC in Northern AL. The aft cabin was fine at night, roughly the size of the R21EC cabin. The foreward cabin AC unit was marginal, a smaller cabin than a R25.

gene
 
We have a 16,000 BTU on our 27 and it just about kept up with the 85 degree weather during the day in Key Largo during March. Never heard of a 12 volts A/C.
 
We need our generator running to run the A/C on the R29. I would think any 12VDC???? A/C unit would drain the batteries (via an inverter) in very short order.
 
Our 21EC has the 12 v a/c unit, and it struggles to keep the cabin under 85 on a warm, sunny day. What we do is have a d/c fan running to assist in circulating air in the cabin - it helps. The other thing that you need to do is allow the unit to cycle off so that the batteries have a chance to recharge. if the unit runs constantly, the batteries will discharge in about 3-4 hours even if on the charger. I set the a/c temp a few degrees below the cabin temp, let it cool the cabin slowly, and after it shuts down for a short time, reset the thermostat a few degrees lower. You will never get the cabin 'really' cool during the day, but it takes the edge off, especially with the fan. We also put reflective squares cut from auto windshield shades in the roof ports which helps.
At night when at a marina, we run an electronic fan and do the same trick to allow the unit to cycle and batteries to charge. At night, it is very comfortable to sleep on the boat in the summer. WJC
 
Wefings has more experience in Florida than most with these Marvair 12 v A/C units . The factory installation is fine for being underway with the 80 amp alternator pumping out DC to the 2 Group 24 deep cycles that are isolated and dedicated to the A/C .Its not designed to refrigerate a boat in the hot climate of Florida, but it makes a significant difference with the door closed . Its an aid to day cruising comfort and a near necessity and mostly designed for over nighting . When at anchor [with window covers deployed] , the 2 standard group 24s unassisted are woefully inadequate for any long term 12V A/C usage .2-3 hours maybe, then the unit will shut down or the fuse will blow . If your intention is to shut off the motor after a nice day on the water at anchor, [w/no shorepower] you need to add some serious battery power. in reality 4 group 27s or 3 group 31s would give you a night of cooling . You could go 4 T 105s golf cart batteries as well .The weight is no problem as the R 21 EC can handle it in the stern.With shore power ,the 20 amp charger will keep up with a fully charged set of stock batteries for a while ,but you need more amp hours of storage to make it trouble free. Your South Florida dealer can assist with the proper mods to make it work .They can call me for suggestions . We work together well. BTW the original no duct installation didn't work well,the new ducted install is far better
Happy to help,
Enjoy that great boat !
Marc Grove
Wefings Marine
 
I inquired about the air conditioner when I ordered my R21-EC. They said it would only work at the dock and would not work well when underway or at anchor. I could not see spending that much money for something that would only work at the dock.

I did order the batteries for the A/C so I could install an inverter. If you do that, make sure you get the 2 golf cart batteries connected in series and not the 2 type 24 batteries connected in parallel. The type 24's just do not provide enough juice.
 
Thanks to all for your prompt relies, this site is a great source.

We are looking forward to our July delivery.

Regards,

Phil Rudin
 
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