Air to Air Single split AC

[Octopus]

In a few weeks time I'm taking delivery of a Lagoon 420 with no AC (too expensive). In November, we will be heading across the pond to the Caribbean. We Brits don't generally bother with AC, but it would be nice to have, for occasional cooling and heating. The cost and the weight argue strongly against installing a marine multi-split water to air AC system.

However, I happen to have a new highly efficient reversable 1200 btu air to air single split system that only cost a few hundred dollars. What's to stop me installing this? There's a suitable position on deck behind the helm for the out door unit which could double as bench seat when not in use. The indoor unit could be used to heat/cool the saloon and, when necessary, the air could be persuaded to circulate to heat/cool the 4 cabins. We would probably only use it to cool the boat in the evening to allow sleep to claim us.

The AC unit is a highly efficient (COP 4.0) inverter controlled system that would not be huge burden on our 17kVA generator (with sixteen 210Ah batteries) electricity supply system.

Sure, the outside unit is not built for a marine environment and will eventually corrode, but we would keep it covered when not in use and wash it down with fresh water if necessary.

So, is this a dumb idea? Would the outside unit corrode in weeks? Would 12000 btu be sufficient (given that we would only want to bring the temperature down to bearable levels 25C/77F)?

Chris
L420, #52, Octopus

[ssullivan]

Chris,

You have nothing to lose by giving it a try. I have a non-marine genset out on deck that has been out there for 2 years. It runs the whole boat's power when we are at anchor. The genset looks in close to new condition. Surprisingly little rust.

I think covering something at all times you are not using it goes a long way to avoiding corrosion, which is often due to fog/spray/mist (especially of the salt variety).

When it finally corrodes or gives up, you can purchase a replacement, or go for the marine unit if you like.

[GordMay]

An A/C condenser is designed to live outdoors, and provided it’s protected from mechanical damage and kept clean, should render years of service.

A 12,000 BTUH A/C should adequately cool between 750 to 1200 cubic feet of occupied space.

[Whimsical]

Originally Posted by GordMay

A 12,000 BTUH A/C should adequately cool between 750 to 1200 cubic feet of occupied space.

Bugger
That means A 40' cat would need 50 or 60,000 btu's
May have to cross aircon off my wish list
Mike

[LtBrett]

I don't understand why you couldn't find a home for a couple of self-contained systems. Not terribly expensive. I'd put in three: one for each hull and one for the salon. And forget about operating them on battery. That little 1200 (even if you meant 12,000) btu system is way undersized, unless you dedicate it to the cabin you sleep in.

Brett