Air conditioning

[Banooma]

Completely naïve quest here: in searching for my next boat, I am trying to tackle a few improvements to my boating life. One of the lesser-but still important- factors is air conditioning. Much as I love staying on the boat, some weather is just not conducive to a good night's sleep - at least for my family. On the current sailboat, I've effectively used a portable air conditioner unit to help mitigate very hot and especially humid nights onboard. I am sure the Home Depot purchase was not intended to survive the marine environment for very long, but it is much much cheaper, lower maintenance and less invasive than a marine reverse cycle air conditioner/heater. Purchasing a used boat without is also a cheaper alternative. Aside from the space a portable unit occupies, the ugliness of a visible exhaust hose, and, I assume lower efficiency, what are the arguments against a portable air conditioner? For those of you who use one or the other, how did you weigh this comparison?

 

[Scott T-Bird]

I'm not sure why you think a reverse cycle is invasive. It's mounted out of the way and effective and I'm not sure what maintenance you are thinking of. Compared to a portable mount that you have to put away every time you go sailing? Is this a trick question? @Ward H had a portable mount on his Catalina 30 for a season or 2 before switching over to reverse cycle. I'd bet that when he responds, he will tell you there is no comparison when it comes to convenience and space. I think that you will be most satisfied in seeking a used boat with reverse cycle. I doubt it will make any difference in the sale price. If you compare sailboat pricing, I suspect that you would not be able to discern a difference in pricing based solely on the presence or absence of reverse cycle. You may find that boats that include reverse cycle may be priced higher based on the overall number of upgrades that the owner has selected compared to a bare-bones boat. Based on my experience a few years ago ... the more upgrades the better the deal. When you buy a used boat, you are getting the upgrades at wholesale maximum and often they are nearly free. Would you rather pay retail for upgrades after you purchase the boat? It all depends on what you want. I would never buy another boat in New Jersey or further south without built-in air conditioning now that I know the difference!

 

[Banooma]

Not a trick question - I told you it was naive! Sorry if I misunderstand the whole installation, but my impression was that it involves the creative effort of locating the components and routing ductwork around existing systems and still staying out of the way, in addition to adding a through-hulls. I agree it's probably in my best interest to find a boat with air conditioning pre-installed but I wanted to hear opinions. Thanks for yours, Scott!

 

[ggrizzard]

Banooma, you are correct in your estimation of steps required to install a A/C system from scratch.
I have used various window A/C units for years and found that at $200 a pop, I can find a place to stow the thing. I don't mind ugly. I don't mind losing 6 cubic feet of storage space in my quarter berth 'Garage'. I do mind spending $2 Grand or more on a system that will cost another $500 every time something breaks/wears out.
But, I guess I'm Old School.

 

[Barnacle Bill]

I have installed new A/C units and it really isn't so difficult, if you are handy. Wabasto has various size units that neatly fit into tight spaces. I enjoy both the cool air and the heat depending on the weather. You need an electric A/C pump that takes water through a thru hull and a strainer and the hose then goes directly to the unit. Then there is another hose that goes from the unit output to a thru hull out the side of the boat. Another hose to weep out condensation leads to the bilge. A control box to operate the heat and cold and fan is installed in a convenient location and the wire to that plugs into the electrical box which goes with the unit. It is all plug and play. There is a mother board inside the electrical box, but you don't have to mess with that. I have even replaced a motherboard and that gets tricky remembering where all the wires attach, but not required as everything is already done for you. And you also can get a remote control box thing to operate the functions of the unit. Of course you have to run the A/C wires to the electrical box, but that is no big deal either. I haven't mentioned the duct work. Your Catalina 28 isn't so large where you might need ducting. Different models have a fan blower to send either cool or heat to the cabin and you might get away with just one register at the unit, if it is installed under a berth, for instance.

 

[Ward H]

As @Scott T-Bird said, for the first 3 years of owning my C30 I used a 5k BTU window unit sitting on a tray I built and blowing into the forward hatch over the v-berth. I fashioned some plastic downspout to focus the cooled air into the cabin. Worked well but I got real tired lifting it up into the hatch after a long hot day of sailing and removing it the next day to go sailing. Plus it was just getting to heavy for me to lift in and out of the hatch.

I looked at the portable units but they were inefficient and took up too much floor space.

Last spring I decided to install a 10k BTU Webasto unit. I studied the web for locations for install on a C30 and decided the hanging locker would be a good location for us. We sleep in the main cabin so installing the unit in the hanging locker with a vent through the starboard bulkhead worked out well. The intake is through the hanging locker louvered door. This location required little duct work.
I've replaced all my thru hulls previously so installing a new one with strainer and pump was no big deal. I have also re-wired most of my boat so running the electric was simple. I didn't want the condensation in the bilge (not recommended in the install instructions) so I used a Venturi set up to draw the condensate out of the pan under the AC and discharged it with the cooling water.
It took a bit of planning but wasn't difficult as a DIY project.

After a long day of sailing in a heat wave, to be able to pull in the slip, connect to shore power, flip a breaker and have a cool cabin by the time the boat is settled away is priceless. My install was about $2,600 and probably doubled my sailing this past summer when we had something like 6 heat waves.

We have friends in the marina with a C34. They did their own install which included ductwork to main and rear cabin.

I agree with Scott, if I was looking for a new boat I would factor in the price either AC already installed or putting a system in.

 

[BarryL]

Hello,

How large a boat are you looking for. If it's a 30' or so, then using a smaller window type air conditioner would be pretty cheap and easy to do. If you are after a 40' boat, that's a different story. Last year I bought a 40' Jeanneau with factory reverse cycle AC and heat. I have 2 AC units, one for the aft cabins and another one for the main salon and forward cabin. There are ducts to each cabin, each head, etc. It's a complicated system and would be very difficult to add as an aftermarket system. IMHO, if you want a boat with air conditioning, buy a boat with air conditioning.

I only used the air conditioning a few times. It worked very well and I really enjoyed being cool and dry when it was hot and humid. Sleeping was very nice instead of tossing and turning on damp bunk.

Good luck,
Barry

 

[Scott T-Bird]

Not a trick question - I told you it was naive! Sorry if I misunderstand the whole installation, but my impression was that it involves the creative effort of locating the components and routing ductwork around existing systems and still staying out of the way, in addition to adding a through-hulls. I agree it's probably in my best interest to find a boat with air conditioning pre-installed but I wanted to hear opinions. Thanks for yours, Scott!

You're absolutely correct that the installation requires a lot of effort. Ward's example is perfect. He has great mechanical skills, but I know that it was not a simple installation. Since he bought a new unit, he paid retail. Yet, even with the effort and the cost he says it was well worthwhile! I am thinking that in the context of purchasing a used boat, the installation is already done and you can verify it. Plus, you won't have the expense. Nobody is going to get $2,600 extra because there is a functioning air conditioner on the boat. That's pretty much a throw in, but it does mean it will be more attractive to other buyers so you won't have as much negotiating room.

If you like your Catalina (and I suspect you do), you will love a Catalina 320 as much as I do unless you are in the market for something substantially bigger. I do have one complaint about the reverse cycle unit, though. It is very loud and it is separated from the aft cabin by just a thin fiberglass panel. I find it too noisy for a decent night's sleep. I usually turn it off overnight, when it cools down toward midnight. Only a few times have I slept in the aft cabin with it on overnight. It is much quieter in the saloon.

There was one night I woke up with the air conditioning blowing heat on me! I had the thermostat set at about 75, I think. I went to sleep with it blowing cool air, but the air temp outside dropped and in the wee hours, the air temp dropped low enough to trigger a call for heat!

 

[kloudie1]

I used a unit in the companionway for a couple of years then I got tired of humping the thing to the back cabin or out to the car when the kids started using the back cabin. I bit the bullet when West Marine put units on sale and included free shipping. It took a good bit of head scratching to figure the placement for things to go .. I installed it in 1994 and wouldn't be without one down here in Louisiana. A big benefit is that it has a "dehumidify" cycle that keeps the moisture at bay when we aren't aboard. It stays on all the time. The only downside is that ya have to be on shore power to run it..

 

[Banooma]

I do like my Catalina and feel a step up to another Catalina is the best way to go for a lot of reasons. It appears it will just require a little more patience to find the right one in this market. Thanks for all the advice - I think the best bet for me is to find one that already has AC installed, unless it is discounted only for that reason. At this point I'm widely looking at the 320, 34 and 350. Maybe this is unsurprising - the only ones I'm finding that are not already under contract, do not have AC.

 

[Scott T-Bird]

I see that ... there are not nearly as many on the market as we had 2 years ago. There are a couple of attractive boats in our area for both the 320 & 350. Air conditioning would not be a difficult install, especially when you can see how it is set up in other boats. We're nearby ....

 

[Tally Ho]

As @Scott T-Bird said, for the first 3 years of owning my C30 I used a 5k BTU window unit sitting on a tray I built and blowing into the forward hatch over the v-berth. I fashioned some plastic downspout to focus the cooled air into the cabin. Worked well but I got real tired lifting it up into the hatch after a long hot day of sailing and removing it the next day to go sailing. Plus it was just getting to heavy for me to lift in and out of the hatch.

I looked at the portable units but they were inefficient and took up too much floor space.

Last spring I decided to install a 10k BTU Webasto unit. I studied the web for locations for install on a C30 and decided the hanging locker would be a good location for us. We sleep in the main cabin so installing the unit in the hanging locker with a vent through the starboard bulkhead worked out well. The intake is through the hanging locker louvered door. This location required little duct work.
I've replaced all my thru hulls previously so installing a new one with strainer and pump was no big deal. I have also re-wired most of my boat so running the electric was simple. I didn't want the condensation in the bilge (not recommended in the install instructions) so I used a Venturi set up to draw the condensate out of the pan under the AC and discharged it with the cooling water.
It took a bit of planning but wasn't difficult as a DIY project.

After a long day of sailing in a heat wave, to be able to pull in the slip, connect to shore power, flip a breaker and have a cool cabin by the time the boat is settled away is priceless. My install was about $2,600 and probably doubled my sailing this past summer when we had something like 6 heat waves.

We have friends in the marina with a C34. They did their own install which included ductwork to main and rear cabin.

I agree with Scott, if I was looking for a new boat I would factor in the price either AC already installed or putting a system in.

What sort of electrical upgrades are required to install a 10k btu unit? I am pretty good with the mechanical and plumbing work, but not sure if my boat electrical system would be sufficient for a 10k but unit.


Greg

 

[jeepbluetj]

What sort of electrical upgrades are required to install a 10k btu unit? I am pretty good with the mechanical and plumbing work, but not sure if my boat electrical system would be sufficient for a 10k but unit.

You need a dedicated 120v 15A circuit. Some folks add another 30A inlet (what was done to my boat, poorly, by pros.). I would have just added a breaker to the existing 30A service and not made hot water and cold air at the same time. 10K btu will pull ~7A or so after it's started.

Normal boat wiring rules apply, stranded marine wire, keep 120v and 12v separated, use correct breakers, etc.

 

[heritage]

A 10k btu marine ac will draw about 1000 watts. My 4.5 btu ac uses about 500 watts. I can run it with a 1500 watt invertor at anchor which will pull 42 amps from the batteries. Can't run it for long though, but nice on a hot, humid night. I do have a large LI battery bank.

You should run a dedicated 10-12 awg cable from your 30 amp service panel to the ac. Your 30 amp service can support a total of about 3400 watts, so you should not need a second 30 amp service unless you plan to run the ac and several other high draw devices at the same time.

 

[thinwater]

And in case you are not aware, AC is a dock-only thing, unless you have and run a generator, or possibly, with some very interesting upgrades to the solar and battery system (which bleeding edge and I am fairly sure is beyond your scope of work).

 

[Benny17441]

A portable A/C unit is very inefficient for a boat. The cooling air for the compressor is exhausted via a hose which heats up and acts as a heat radiator inside the boat. Also the volume of air discharged to the outside is significant and must be replaced to the inside of the cabin. The replacement air will be drawn from the outside hot and humid air through every nook and cranny in the closed cabin. These portable units are designed to and work fairly well in a room in a home as they are usually well insulated and can draw relatively cool air from other rooms, but a boat is not well insulated and the air must come from the outside. What is better to use in a boat as a cheap alternative is window unit as it utilizes outside air to cool the compressor and just recirculates the existing air in the cabin without drawing air from the outside. People usually place them in the companionway secured by one the door slats with some insulation to cover any openings. You can very well run a 6,000 BTU unit with 2000 Watts generator with minimum noise and fuel consumption. None of these home or marine units are efficient enough to be ran from batteries for an adequate period of time. RVers are utilizing solar panels, inverters and Lithium battery banks costing thousands of dollars and they can only run A/C for a few hours. So on the water a gas powered generator still offers the cheapest alternative. Gasoline aboard does offer some challenges and must be handled very carefully.

 

[Ward H]

What sort of electrical upgrades are required to install a 10k btu unit? I am pretty good with the mechanical and plumbing work, but not sure if my boat electrical system would be sufficient for a 10k but unit.

Yep, as others said I ran a 10-2 w G from an spare 15 A breaker to the AC control box. Then wired in the water pump. Wiring from the thermostat and from the compressor just plugged into the control box.

 

[Ward H]

Air conditioning would not be a difficult install, especially when you can see how it is set up in other boats. We're nearby ....

Scott's correct. I was hesitant to start the project until I saw how it was set up on Scott's boat and how well it worked.

IF we were looking for out next boat and we are not, we would look for a C320. I like Scott's much more than the C34.

 

[Tally Ho]

You need a dedicated 120v 15A circuit. Some folks add another 30A inlet (what was done to my boat, poorly, by pros.). I would have just added a breaker to the existing 30A service and not made hot water and cold air at the same time. 10K btu will pull ~7A or so after it's started.

Normal boat wiring rules apply, stranded marine wire, keep 120v and 12v separated, use correct breakers, etc.

Thanks for all of the info…this is something I wasn’t sure of…I see a lot boats with 2) 30-amp cords and I thought that I needed to add another 30-amp service to run AC. Sounds like I would not need that. I get the dedicated breaker and wiring to the AC unit…that is not too bad.

Thanks…all good info.

Greg