cuddy-cabin air conditioning without Genset

[kmurray802]

Has anyone tried the low amp a/c units that claim to run off of an inverter?(no generator required).

 

[tashasdaddy]

Re: cuddy-cabin air conditioning without Genset

it's fine when you are cruising, but do you want your engine to idle while anchored. doesn't sound good to me.

 

[Texasmark]

Re: cuddy-cabin air conditioning without Genset

Do a real quick calculation of the watts (volt-amps.....don't worry about the power factor for this calc) required by the A/C and the output of the inverter at some operating point.

Also, remember that an inverter is just a power type converter (DC-AC), not a generator which is making watts from some sort of power/fuel source. So if a battery is powering your inverter, you have to get the same power drain (plus losses) put back into the battery.....so what's gonna do that? Your alternator on your outboard? Better check the numbers again.

You'll find out real quick that you ainna gonna get there from here.

Mark

 

[kmurray802]

Re: cuddy-cabin air conditioning without Genset

I'm with you. I just don't see any way these could work well.I've been in the a/c business for 20 years.One of the biggest killers of compressors is low voltage.
Low voltage = high amperage causing high heat and premature comp. failure.
I'm not interested in buying one,I'm just curios if anyone has actually tried one and if it worked or not.

 

[jlinder]

Re: cuddy-cabin air conditioning without Genset

The first question I want to know is how much power is needed (in watts)?

I looked on the internet and found a small very efficient 5,200 BTU unit that draws 4.4 amps at 120v.

Optimistic calculations would give 44 amps at 12 volt with an inverter, assuming no loss. Pretty heavy load.

 

[drewpster]

Re: cuddy-cabin air conditioning without Genset

I wonder if a small gas generator like one of those little Honda jobs would have enough juice to carry a small AC?

 

[kmurray802]

Re: cuddy-cabin air conditioning without Genset

I'm sure that it would power a small a/c unit.I just don't know how safe it would be.I would think you would want a marine gen.that is installed in a dry,secure location.By running generator(even small one)you are creating high voltage electricity which does not mix well with water.
Also you have the exhaust to deal with.It must be discharged out and away from boat.
I guess if you where just out for the day, if you could strap it in a 100% dry, well ventilated area it might be o.k. but I would never attempt to over-night with it.
It would be nice if they where usable.You can buy 4 or 5 small regular gen's for about the same price as 1 small marine gen-set.

 

[drewpster]

Re: cuddy-cabin air conditioning without Genset

I understand that it would have to be well ventilated. My idea was to use the gen out on the deck temporarily. Then stow it when not in use. They are quite small. I was just wondering about how many watts it would need to be to power an AC. Just a thought.
I was looking online at a unit that is designed to work with an inverter. The AC package is the size of a battery box. However I think it said you needed over 300 amp/hrs battery capacity to run it eight hours. Thats why I thought of the small gen idea. Some are advertised with a sine wave inverter as part of the gen. Its moot in my case anyway the 12 volt AC I was looking at is more than I can afford anyway. ($1000+)

 

[ZmOz]

Re: cuddy-cabin air conditioning without Genset

I'm with you. I just don't see any way these could work well.I've been in the a/c business for 20 years.One of the biggest killers of compressors is low voltage.
Low voltage = high amperage causing high heat and premature comp. failure.
I'm not interested in buying one,I'm just curios if anyone has actually tried one and if it worked or not.

The A/C would run off the inverter, (115v) so low voltage wouldn't be an issue. I just bought a 5200 BTU A/C ($99) rated at 535 watts. It runs fine off my 800 watt inverter ($50) connected to a 39ah battery. (just playing with it, not going to use it this way) It draws about 50 amps at 12v. You could run the A/C for an hour from a big deep cycle battery, but you'd have to replace all those watts somehow.

 

[drewpster]

Re: cuddy-cabin air conditioning without Genset

OK here is what I have found. This AC package unit,

by Mermaid Manufacturing will run with this generator,

But here is the hitch, The AC unit is in the $1200 to $1400 range and the generator is in the $400 to $600 range. Not including installation or the do-dads you will need to get things going.

Whew! It costs through the nose!