Using home air conditioning units on a boat?

[Coolerking]

Show me where, on a Viking sport fisher, you can put any of the equipment.
I'll be here waiting until Monday morning, when I'll actually be on one.
Also, you could just look at the Durasea condensers that are right there in the Dometic catalog.
We have done lots of them, on tractor tugs, research vessels, multi deck party boats, but never on a Sportfisher.

[SalingSue]

Seems like a awful lot of units for that boat.

Per the home AC, the only way I have seen that work was the little portables with the duct going out a window, or the ones you drop on a hatch, in both cases they are removed and stored somewhere when the boat is underway. Mostly used as a cheap stopgap, not a long term solution.

I’d look into why that boat needs that many, maybe getting a good tint on the windows, checking the efficiency and health of the existing AC units, adding insulation, etc

[DeValency]

Originally Posted by skipmac

Relative upgrading his Viking 56 sport fisherman. Latest project is the air conditioning system.



The boat came with five units. I believe that's five separate compressors with associated evaporators/blowers. He thinks the units are 7-8 years old and just spent a good bit on maintenance.



He's thinking about upgrading due to the age and hours on the units and is considering using home units, what he calls a split system. That I believe means a separate compressor/condenser with evaporators/blowers in the different cabins. The reasons, cost and simplicity by eliminating all the raw water pumps, heat exchangers, etc.



The compressor would be air cooled home unit installed in the engine room with a pair of Mann 1550 HP diesels. That doesn't sound like a good idea to me. Certainly in that heated environment the air cooling would be very inefficient and also lead to a shorter life for the compressor as it would run very hot. Also the smallest unit he could get would be rated for a house at least double the volume of the boat so it would be running much under capacity which I think is not recommended.



So can any HVAC experts confirm my opinion that this would be a bad idea and why? On top of any other comments I could make I have to think that if it was practical why isn't everyone doing it.

It isn’t such a bad idea for a larger motor boat (large decks to mount the external compressor etc.) Unfortunately, for most actually sailing sailboats it isn’t a viable solution, due to limited and busy deck spaces. Split systems are more efficient and save internal space. I’ve seen many dock queens sailboats with domestic split systems that work perfectly.

Price wise - a fraction of “marine HVAC”. The fact they survived 7-8 years proves this even more, not to speak about the expensive maintenance that only specialized marine systems experts can do.

I hate to bring into the boat more cooling water than necessary with the extra thruhulls plumbing etc.

Yes, the external compressor may get rusty faster (can be well delayed with a good preventive maintenance). And if you need to replace it with a new one the cost would be $2-5K maybe every 5-10 years.

[prajna101]

I just installed a house portable air conditioner in a closet and piped the exhaust to a port. AC, Heat, and Dehumidify. $200 and about 10 min to install. If it dies every couple of years, I can replace many times for the cost of marine AC on board.

[MultiCountryDon]

I have an RV and a few boats.
Unless the RV is falling down a mountain it will never see forces equal to the ocean at war. Normally called a storm.
And yes, I take the RV boondocking.
Don

[Chotu]

Originally Posted by MultiCountryDon

I have an RV and a few boats.
Unless the RV is falling down a mountain it will never see forces equal to the ocean at war. Normally called a storm.
And yes, I take the RV boondocking.
Don

Cape Coral? Please. You haven’t hit a bump in your life. Florida roads are the best in the country.

When your suspension completely decompressed and you feel zero gs for a brief second before slamming down after hitting a whoop or are rattled so hard by road “chop” that things in the RV fall apart and dishes break while still stacked neatly in the cabinet, let me know.

Boats have nowhere near the G forces. It’s tiny acceleration in comparison. You’re not even in contact with a solid object.

I know people love to over exaggerate all things nautical, but come on. It’s a liquid. The boat never comes to a hard stop like you do on making contact with the ground. The entire situation is a built in shock absorber as the displacement keeps going up when the boat presses down. Then it comes to a nice soft stop and goes back in the other direction.

Unless of course you have a flat bottom skiff in heavy chop at WOT? Maybe that’s what you’re talking about?

[MultiCountryDon]

No skiff, but did hit an unmarked coral protrusion with a previous sailboat. 6 knots to zero within 4 inches. Yup, everything inside ended up on the floor.
Roads in Florida are ok but covid19 sent me to the back roads in other states. Still think boats get more punishment.
BTW- looked at a boat in Brunei in January this year. It had the split domestic aircon. Besides being ugly with that apparatus on the deck, it had quit working after a year.

[billgewater]

Some locals here in Aus, recently acquired a US motor boat loaded with American mains powered accessories. Including a swathe of air conditioners. The only way they can use the air conditioners, microwave etc. is to run their gen set as our mains (marina) voltage is 240 VAC at 50 Hz. Seems that the long and short of it is that they will have to replace all the units plus the wiring plus (probably) the gen set. Ouch.

[GoneDiving]

Originally Posted by billgewater

Some locals here in Aus, recently acquired a US motor boat loaded with American mains powered accessories. Including a swathe of air conditioners. The only way they can use the air conditioners, microwave etc. is to run their gen set as our mains (marina) voltage is 240 VAC at 50 Hz. Seems that the long and short of it is that they will have to replace all the units plus the wiring plus (probably) the gen set. Ouch.

No offense but how can that be a surprise? I stopped looking at Hatteras LRCs for that exact reason. Importation and conversion was going to cost as much as the initial purchase (maybe I'm exaggerating but you get the idea) 😩

Frequency converters are available and some 60hz items can run on 50. Most would agree adapting 50hz to 60 is easier than the other way but neither is painless

Good luck to your friend. 😊

[AndyinAbudhabi]

We're living onboard full time in the Middle East. We, along with almost all other livaboards use household split systems. Much more efficient than marine systems. Also water temperature here during summer makes the water cooled marine systems pretty much ineffective.

[Sailmonkey]

Originally Posted by AndyinAbudhabi

We're living onboard full time in the Middle East. We, along with almost all other livaboards use household split systems. Much more efficient than marine systems. Also water temperature here during summer makes the water cooled marine systems pretty much ineffective.

Can you post photos of where you installed the condenser(s)for your split?

[skipmac]

Again thanks to all for the input. I had not expected the diversity of opinion on the matter.

Spent some family time over the weekend and asked SiL a few more details.

First, as a building contractor he has installed a lot of home units so is very familiar with the sizes and types available and the space in his engine room. He's quite confident that the units he's looking at will fit easily.

These are not what I thought IE a compressor unit feeding large wall mounted evaporators but instead would go to evaporators in the engine room that would feed the cool air into the existing ducts.

He has two, related reasons for considering the home units. First he's having problems with the existing units and even after spending a bit on a recommended repair expert he's still having problems. Also, his go to Viking guy who manages a number of them for absentee owners and seems to know them pretty well, complains that the biggest, ongoing problem he has with all the boats he manages is the air conditioning system, even on relatively new boats.

Other comments.

The boat does have dark tinted windows but only one opening hatch on the entire boat so ac is a must. Also a must because there's thousands of pounds of engine block that gets quite warm and holds heat for a couple of days.

Boat has three sleeping cabins and a large galley/saloon area each with separate controls and I assume independent evaporators. I'm told there are five so assume the galley area is cooled by two.

[Sailmonkey]

So the consideration is now placing the condenser and the evaporator in the engine room?

Great pains will need to be taken to isolate cabin air from machinery space air. Both for odor as well as gasses (exhaust primarily).

[s/v Jedi]

Of-course you can take a modern inverter split unit and replace the condenser with a water-cooled condenser...

[skipmac]

Originally Posted by s/v Jedi

Of-course you can take a modern inverter split unit and replace the condenser with a water-cooled condenser...

Thus ending up back where you started.

The water cooling seems to be where he's having the most problems.