How to run an 18000BTU A/C at Anchor

[Svan]

The generator would be distributing 120v to your boat systems, including charger, but also direct to the AC.

You should buy more fans. This is a bad plan.

[Sailsman10]

I have a flagship 18000 btu I run with my Honda 20001 generator. .?

[S/V Alchemy]

Originally Posted by ed2068

Thanks for the video RSN48. What I meant about economical was not installing a $9k dollar generator on the boat. Do you think that it would be able to run with the soft start and a small 2200 generator? I think that the cost would be around $1000.00 to install.

No. I have a 3000 watt inverter and a nearly 1200 Ah 12VDC bank, four 135 W panels and a 400w wind genny and just a 12,000 BTU Marine Air heat pump/A/C unit, but I wouldn't do this off a dock unless I had two Honda EU2200s ganged to cover the drawdown.

The kick on the March pump at start up is 17 amps on the VAC side; the A/C draws 6 amps DC continuous, as I remember. It's a big ask of a small bank, especially if you want to run a fridge at anchor as well, never mind critical stuff like bilge pumps.

Run the numbers to verify my ballpark figures here.

[JDanielBryant]

I'm afraid the math doesn't work in your favor here; the wattage requirements for an 18,000 BTU AC are just too great. Best option would be a Next Gen 5.5kW inboard diesel genset, but it will run you $7K. Don't bother with the $400 Harbor Freight gas generators - the noise is deafening and the fumes worse.

[ed2068]

The a/c is 120 v. to be used while on shore power. Sand Crab I saw the same video about the 16k btu and that was the reason I thought a 2200kw -2500 kw genset with an easy start would be able to power the a/c. But I guess I will be taking in your comments and start putting in larger fans. I have tried 2 iGen 2200 in parallel. They started the a/c 2 times but after that, they would not power it up again, one if the gensets would turn down. Also, the noise level and vibration were high.

[ed2068]

sailsman 10 Mine is also a Flagship 18000 btu. how do you run it with the Honda 2000?

[akprb]

Originally Posted by chowdan

I'd ditch the ac unit. Save yourself the cost of not just getting a system to be able to handle it, but the cost to run it. Itd open up space for more storage.

Wind scoops, 12v fans properly placed can help create a good draft at lower power consumption. Not economical to run AC unless you are on shore power

I take it you have lived at anchor in S. Florida in August during prolonged rain??? :-) (full disclosure I did long ago, not a functioning model)

You are right, shore power or a good sized generator.

[Chuck34]

Originally Posted by stormalong

No way without a 5 kw generator.

Open the hatches, add a windscoop or two and enjoy the silence.

My dock neighbor has a 16k BTU AC unit that he runs on his Honda 2000. I was shocked when he told me this as I never thought the Honda 2000 could run any AC unit that big.
My boat also has a 16k unit so I asked if I could try his Honda on my unit. Ran just fine.
My point...just maybe a Honda 2200 will run an 18k unit. If you know anyone with the 2200, ask if you can try it out.

[chowdan]

Originally Posted by akprb

I take it you have lived at anchor in S. Florida in August during prolonged rain??? :-) (full disclosure I did long ago, not a functioning model)

You are right, shore power or a good sized generator.

I haven't live at anchor in Florida, but have lived at anchor in Fiji. Regardless of rain, getting covers setup to keep hatches cracked and fans moving air is what I found to work best. I also found having the shade up helped break the sun from beating down.

It was the worst before the rain as humidity and stillness was at its worst.

[bradfordharley]

I personally wouldn’t do anything portable except Honda. There is a reason they are the standard for portables.
First, plug into dock and measure startup and running amperage. You could Buy two Honda 2200’s and chain them togetherr for 4.4kw peak.
You will probably need a soft start kit and/or in inverter that has a power assist—check out victron. You will burn up to 1 gallon every 90 minutes.
I personally don’t think it’s worth it and we didn’t run our AC the entire summer in the upper sea of Cortez which is very hot. Just not worth it for us, but your situation may be different.

[a64pilot]

July and August are pretty much unbearable in Fl.
Of course you can do it, if your healthy it’s unlikely it will actually kill you, you just think your going to die.

Why would anyone intentionally subject themselves to that?

Long term sustainability wise you have two options,
1. Move North
2. A slip with shorepower.

If you try to run a generator to provide air conditioning, your looking at 100 hours a week minimum, and even then your still going to sweat some.
Fuel cost and oil changes, repairs and amortization of the generator costs more than a slip.

People who say just cool the boat down and then turn it off haven’t actually tried that in Fl during July and August. It’s Africa hot then, and no wind, no breeze.

[Sand crab]

Those portable aircon units are pretty affordable. Buy one and if doesn't work with a 2200 Honda then send it back.


BTW Florida is frikin hot. I grew up there. I sweat. I need AC. Now in the PNW where the weather is more to my liking.

[Squanderbucks]

The are many who would suggest going the portable generator method but I disagree from a practical and safety point of view. If you don't feel you have the room for a fixed in place generator in your boat - how will you find the room for possibly two portable ones, their cord sets and then have to move them around to set them up in a safe, out of the rain and also avoid the exhaust going into deck or cabin places.

I don't think this is really something most people would be satisfied with for very long. If you were in a place where you might set it up once in a while and leave it in place for a while before breaking it down and moving back to storage - then maybe.

A marine genset tucked away in it's own space doesn't require anything but a one time setup and then periodic maintenance like the main engine. Also it usually is more fuel efficient and definitely less noisy tucked away. Fuel usage is always a consideration for boats. I suspect that a 4 KW diesel would burn approx 12 Gal/24 max hours runtime.

Cost estimate for a real generator and not something like a Panda would run you about $5-8 thousand dollars plus installation which you could save if done yourself depending on the size you bought.

Elsewise you are just already setup to use the A/C while at dock as the original owner intended.

[Pdemajo]

Hi Ed. I have a 16000 marine unit and i run it reliably with a honda eu22i...

[Augi]

Originally Posted by ed2068

Hi Everyone :
I have a 38´sailboat that we purchased 10 months ago. We live in S. FL. and the summer months get brutally hot. There is an 18000 BTU A/C on board, but no Genset. There is no room to put one in, as space is limited and extremely expensive. I have (2) 4D AGM parallel Batteries as house bank and (1) 4D AGM for the Magnum 3300 KW inverter. (4) Solar Panels at 80 Watts each. It had an Eclectic wind generator which was not on the boat when I bought it. All that would be needed would be the wind generation system everything else is in place.

What would be the best and most economical way to be able to run the A/C while at anchor? Would it be with a soft start and a 2200 KW generator? Thru the 120V system or would the inverter be the best way and charge the batteries with the generator? or is there any other way you can suggest?

Thank you in advance for any help that you can give.

Regards

Sail to Maine for the summer is the best idea suggested so far.

Two Honda portable generators, tethered together, one long extension cord so you can put the generators in the dink as far as possible away from the boat so you can sleep. Your neighbors will not be happy with this solution.

If it was me and keeping the boat in New England in the summer is not viable, I would ditch the generator, go with a lot of fans including hatch fans. If it is still, very likely too hot get a slip in a marina and run the a/c off shore power. I would probably just get a slip in a Marina for the 3-4 intolerably hot months in S. Florida if I could not keep the boat some where that is cool in the summer. Better to keep things simple.