I am considering installing A/C in my 1986 Nonesuch 30 Ultra. Can anyone share examples? Did you add another 30amp plug? Did you use a d/c type HVAC unit? Is 5000btu about right for Chesapeake, NY Long Island, Canadian summer or Bahamas winters? Where did you locate it on the boat? did you put in ductwork or just have it blast out in one location?
Pictures are gratefully appreciated too.
I think you’ll get better answers, but here’s a data point, anyway.
In 2022 I looked at an NS33 in San Diego. It had originally been located in New Orleans and so was equipped with HVAC. According to the survey, the brand was “Anchor” and I’m sorry that it did not list the BTUs. The boat had only the one 30A, 120V AC service connection. This setup was apparently satisfactory for NOLA, so it seems like you should be able to set up a similar system for your area.
The NS33 has a dinette to port with a cabinet between it and the forward cabin bulkhead. The HVAC equipment was located inside of that cabinet, with one vent blowing into the main cabin and another blowing into the forward cabin. It was a hot summer day (it does happen, occasionally, in San Diego) and so I turned on the AC when I first arrived for the survey. By the time the surveyor arrived it was very comfortable down below and he was very appreciative. Both the surveyor and the mechanic spent probably more time down below than they would have without the AC and so I assume I got a better survey. That did not work in the seller’s favor, but it did leave me impressed with the AC. I fantasize about installing it on my boat, but have not done it.
I self installed a 5,000 watt HVACunit under my cooktop which I installed in place of the original stove. I only have one short vent to the port side. I used the existing A/C service and did not add an additional shore power inlet. This works fine in the NC heat. The fan I have to the right of the head door blows the air to the front cabin.
Hilary -
Although a water-source AC system is convenient, most sailors I know have a lot of trouble with them. The intakes get blocked by seaweed, jellyfish, and the like, and they shut down or break when that happens. My solution is a portable R2D2 style unit that I keep in the shower stall. It doesn’t require a drain, and I use one of the port windows for the exhaust. It does the job on a hot summer evening on the Chesapeake. Here’s the unit I got: LG LP0820WSR: 8,000 BTU Portable Air Conditioner | LG USA
I probably only use it a few times a year.
Capt. Hilary,
We installed a 12,000 BTU Webasto heat pump in our NS 30U a few years ago and can report zero issues with the unit so far. We chose the 12k model rather than a smaller unit because we plan to sail south in the future, where the extra capacity will be an advantage. Whether you need that much capacity in your area is worth considering, but I can say this: we’ve ended up as the “host boat” more than once during unusually warm spells when the buddy boat’s AC just couldn’t keep up.
Unit Location:
I mounted it in the port-side aft dry locker—the one accessible from inside the cabin next to the AC breaker panel. To support the unit, I built a G10 shelf shaped to match the AC base. This location still leaves enough room in the locker to hang our PFDs and wet foulies.
We have two supply ducts. The first is very short—essentially a hard-fitting discharge directly into the main cabin at the upper-most port corner, close to the hull. The second duct runs to the stateroom and also discharges high and against the hull on the port side. Routing this one took some creativity. With my HVAC background, I knew I needed to minimize bends and restrictions. I used Buck Duct instead of flex duct to keep air resistance down. Hard metal pipe would have been ideal, but installation would require major cutting and patching, so Buck Duct was a reasonable compromise.
Duct routing:
Section 1: From the unit, routed through the cabinet behind the bench seat, mounted high and fully concealed.
Section 2: To access the next run, I removed the oven. The duct exits the cabinet into the space behind the oven, where I installed a rigid 90° elbow and routed the duct vertically into the cabinet behind the stove/icebox.
Section 3: A second 90° elbow turns the duct horizontal along the top-rear of the cabinet and into the stateroom.
Return air:
The unit needs as much return air as it supplies. I created two return paths:
The first is an opening to the left (aft) of the stove that feeds air back into the same cabinet containing the supply duct.
The second is simply leaving the wet-locker door cracked open slightly. (Eventually I’ll install a grille.)
The “oops” and fix:
After reinstalling the oven and sliding the countertop to expose the burners, I discovered the vertical duct kept the counter from opening fully by a few inches. I solved this by cutting a small notch in the countertop to clear the duct and hinging the cutout piece. When the counter is closed, the piece lies flat and the notch is almost invisible; when open, the cutout drops into place around the duct. The fix is subtle—almost nobody notices it (well, except now you).
Condensation and bilge:
All ducting was insulated and sealed with aluminum tape to prevent condensation. The unit’s condensate drains to the bilge into an open plastic container, which helps keep the bilge dry. I also placed my backup bilge pump there.
Seawater plumbing:
The Webasto requires seawater intake and discharge. To avoid drilling any new holes, I repurposed the head’s seacock by adding a 3-way valve. It now feeds the Webasto (its normal position), the anchor washdown, or the head—with only one selectable at a time. We don’t use seawater in the head, so the only time we change the valve is when washing down the anchor or chain, and during those times the Webasto must be off. From the 3-way valve, I routed hose to the bilge-mounted pump and then to the unit. For discharge, again avoiding new holes, I tied into the port seat-drain hose and installed a check valve.
Electrical:
The unit runs on 120 VAC supplied either from shore power (the existing 30 amp) or through an inverter via a 2-way switch. We have solar and a wind generator feeding three AGM batteries. Power consumption has been modest, and at anchor we’ve always had sufficient capacity—at least in the Northeast. If we make it to the Bahamas, I suspect we’ll need to pay a bit more attention to battery management.
Yes, it was a time-consuming project, but well worth the effort. Our plan is to sail north to Maine next summer and to the Bahamas the following year, and I’m sure the added comfort—both heat and air conditioning—will be welcomed. Good luck with your decision, I hope some of your questions were addressed and please feel free to reach out if you’d like any additional information.
Capt. Chip Ott
NS30U #276 · Westbrook, CT
203-506-8023
g.chip.ott@gmail.com
Capt. Hillary,
In my earlier reply, I mentioned that we had installed a 12k unit. I’m not sure why that number came to mind as I was typing, because the actual BTU rating we selected was 6k. We had debated between this unit and a smaller option, and ultimately chose the larger one—which we feel was the right decision, especially with the two zones.
My apologies for any confusion.
Capt. Chip
Capt. Chip
I’m glad that you replied to Capt. Hillary . In my opinion you are the go to sailor that I have met so far. If I ever consider adding AC to my boat I will probably ask you for pointers. In the mean time can you clarify weather your system is 6 or 12k?
Not yet Capt. Brian
6k. I’m not sure where I was going w the 12, except that I had recently installed a mini split that was a 12. I guess I was thinking about that number.
I appreciate the complement but only used what the good lord gave me, which somehow just got me by.
G. Chip Ott
G. Chip Ott
Cell 203-506-8023
Ain’t that just the way things go.