Aircon with reverse flow

C

Coastgal

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We're going to be cruising around the Med in a catamaran next year (can NOT wait!!!)

We'd planned on using fans in summer and installing diesel heating (Webasto) in the winter (we'll be on anchor most of the time, unless we need to run to marinas for storm protection or socialising top-up)

However, someone's suggested retrofitting airconditioning with reverse flow for heating. Anyone done this? Does the aircon actually cool? (We've been on a couple of boats where aircon only seemed to drop the temp by couple of degrees). And does it really heat in the winter? Better than diesel fired? And it sounds like it would cost a lot more to install than a Webasto-type system.

Views from the knowledgable panel would be gratefully received.

Many thanks - Stacey
 
Hadenough said:
Fine if you are on shore power. Nothing that will work economically off DC that I am aware of. Stand to be corrected.
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I have got a 12v HFL Aircon Unit. It has not been in long and I have not really run it in anger (hasn't been hot enough!!!) but it will work off my 500Ah battery bank and the solar panels will keep up with it for two to three hours. I went for 12v on the premise that I can keep the boat cool whilst the sun is keeping the batteries topped up. It certainly brings the temp down at the moment but I am keeping my fingers crossed for when it has to work hard!!!

It won't heat though...
 
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We have a Cruiseair 16,000 BTU system on our boat. It cools very well-down to 65F-and heats to a reasonable 72F. Boat is just under 12 metres.
The boat came from Florida and the system was fitted when she was new.
One of my old racing mates is Technical Director of a refrigeration company. He had a good look at it and said it had never been re-gassed-the nipples are sealed-and that it was in VGC. It is 14 years old.
Downside is that its noisy, and if the sea tempreture is below 4C it does not act as a heat pump quite so well.
Only works on shore power-in our case 120 volts stepped down from 230.
If you plan to have access to shore power it is a flexible system.
 
um, not on a small sailing boat, not really - if you need heat you would use the diesel powered heaters, off 12v - aircon needs too much power i think.

Also the warm air rises, so wd need lots of aircon outlets low down ... whereas aircon outlets are normally best high up in a boat so the cold air sinks. Another reason why it's rubbish.
 
Just had air con installed - mermaid units. In reverse flow they are really excellent at heating. They quickly bring up the temperature and then just tick over with the compressor only engaging occasionally. At the end of last winter when they were fitted they did a pretty good job of heating even with the sea temperature being around 6 c. Obviously as the sea cools it takes longer to extract heat. They work well in air conditioning cycle. They are noisier that i expected and dont cool the cabin as quickly as i thought but are still very effective. They run off the inveter or otherwise mains or the genny. Off the inverter the load on the house batteries is high and an hour in the evening would probably be the routine at most.

Compared with the eber they heat the cabin around twice as quickly i would guess.
 
I have a 35 year old cruise air reverse aircon system. Still working and never re gassed. There are three units , one double for the saloon and one unit each in the two cabins. Can only run off the genny as it pulls 40 amps at 110v. Tried to run it off shore power once through a transformer and wiped out the harbour system. ( long story).
When running in summer at 35c it can drop the ambient temp in the boat to around 22c. In reverse mode during one unforgettable January when there was snow around us we got the temp up to 22c inside with a water temp of around 12c. When running it all happens within a few minutes. Wouldn't be without it and using fans in the aft cabin when we are ashore is no real alternative. So for me aircon 1 fans and heater 0
 
We have one 12000 btu aircon unit for the two aft cabins, cools wonderfully and heats well. But needs genny or shore power, however an eber in the winter draws a fair amount of power form the batteries for fan, so you would maybe need genny to top up batteries sometime. In the summer when tempos rise top 45 deg in Corfu, the AC is a godsend, especially on windless days. When at anchor we run it on genny for a couple or three hours in the evening, our genny is very quiet, with exhaust separator. Never found the AC unit very noisy.
 
tcm said:
um, not on a small sailing boat, not really - if you need heat you would use the diesel powered heaters, off 12v - aircon needs too much power i think.

Also the warm air rises, so wd need lots of aircon outlets low down ... whereas aircon outlets are normally best high up in a boat so the cold air sinks. Another reason why it's rubbish.
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My experience, and that of the last three posters seems at odds with your conclusion.

Have you ever owned-and used-a yacht fitted with air conditioning?

If not, where is your conclusion drawn from?
 
We retro fitted two 16000BTU reverse air units three years ago and they work very well in both modes heating and cooling. We also have two Webasto heaters but rarely use them these days. The difference in cost between the straight air con units and cooling/heating units is negligible so we went for the reverse cycle heating/cooling units.
 
LOL!

Thanks for all your replies. Lots to think about (and particularly the cost implications of the reverse flow systems).

Anyone got/heard anything about the Webasto Blue Comfort integrated air con & heating system?

Cheers.
 
tcm said:
um, not on a small sailing boat, not really - if you need heat you would use the diesel powered heaters, off 12v - aircon needs too much power i think.

Also the warm air rises, so wd need lots of aircon outlets low down ... whereas aircon outlets are normally best high up in a boat so the cold air sinks. Another reason why it's rubbish.
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Too much thinking here and just opinions. 22,716 of them!!!!!

We have a 12,000 BTU Cruisair reverse cycle system - 16,000 BTU would have been a little better for cooling in the Med, but as a heater it is great. It can run off the big battery bank via an inverter as it only takes 1000 watts and delivers 3000 watts output. Very economical if in a marina and you have to pay extra for the lekky.
 
sailinglegend420 said:
Too much thinking here and just opinions. 22,716 of them!!!!!

We have a 12,000 BTU Cruisair reverse cycle system - 16,000 BTU would have been a little better for cooling in the Med, but as a heater it is great. It can run off the big battery bank via an inverter as it only takes 1000 watts and delivers 3000 watts output. Very economical if in a marina and you have to pay extra for the lekky.
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Only takes 1000 watts? At 12v, that's 83 amps! Well out of the battery capacity and charging regime of most smallish boats at anchor. What's your setup to support such loads?
 
GrahamM376 said:
Only takes 1000 watts? At 12v, that's 83 amps! Well out of the battery capacity and charging regime of most smallish boats at anchor. What's your setup to support such loads?
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This is a Liveaboard forum so why do you assume we all have "smallish boats"?

We are 13 metres and are consistently finding that we are "SMALLER" than many other boats at anchor or on the quays!!!!

Since we are full time liveaboards in the Med we chose a "comfortable" lifestyle so have 1050 Ah of Lifeline batteries - now 10 years old. A 2.5 Kva inverter gives us the power to run the 1200 watt microwave, heat the hot water via a 750 watt immersion heater, or to run the air con for an hour or two before bedtime. When low we charge the batteries with a Fischer Panda DC genset that charges at up to 280 amps.

Our solar is only 136 watts supported by a 40 watt DuoGen towing/wind genny. Alternator is 100 amps - about to fit a second 100 amp this winter with switches to turn them on/off or charge via their internal or external regulators. We still use shorepower every 2-3 weeks to get the batteries back to 100% which even with our set up we can never do.
 
sailinglegend420 said:
This is a Liveaboard forum so why do you assume we all have "smallish boats"?

We are 13 metres and are consistently finding that we are "SMALLER" than many other boats at anchor or on the quays!!!!

Since we are full time liveaboards in the Med we chose a "comfortable" lifestyle so have 1050 Ah of Lifeline batteries - now 10 years old. A 2.5 Kva inverter gives us the power to run the 1200 watt microwave, heat the hot water via a 750 watt immersion heater, or to run the air con for an hour or two before bedtime. When low we charge the batteries with a Fischer Panda DC genset that charges at up to 280 amps.

Our solar is only 136 watts supported by a 40 watt DuoGen towing/wind genny. Alternator is 100 amps - about to fit a second 100 amp this winter with switches to turn them on/off or charge via their internal or external regulators. We still use shorepower every 2-3 weeks to get the batteries back to 100% which even with our set up we can never do.
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WOW! What a setup.
 
sailinglegend420 said:
This is a Liveaboard forum so why do you assume we all have "smallish boats"?

We are 13 metres and are consistently finding that we are "SMALLER" than many other boats at anchor or on the quays!!!!
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I don't assume anything. I suppose it's a matter of perspective as to what is small or large. 10 years ago, our 38 foot boat was one of the largest boats on Conwy moorings but now, cruising around, it's quite small and many liveabords live on much smaller boats. Your power setup is way above the sailing boats I know, just wish I had your space for the battery bank and genny. We exist on 200w solar + wind genny + Honda 2kw occasionally and rarely use marinas so, such heavy loads are out of the question. Anyone know of aircon nearer to 10 amps draw? :)
 
GrahamM376 said:
I don't assume anything. I suppose it's a matter of perspective as to what is small or large. 10 years ago, our 38 foot boat was one of the largest boats on Conwy moorings but now, cruising around, it's quite small and many liveabords live on much smaller boats. Your power setup is way above the sailing boats I know, just wish I had your space for the battery bank and genny. We exist on 200w solar + wind genny + Honda 2kw occasionally and rarely use marinas so, such heavy loads are out of the question. Anyone know of aircon nearer to 10 amps draw? :)
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simple answer, no you will not find an aircon which draws only 10 amps, unless its 10amps at 230 volts.
 
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