Southwest Florida has wonderful cruising grounds, but it can be a
little hot in the summer, especially in marinas where we can’t
swing into the wind. After two summers here, we finally decided to
install A/C in Yet To Be, our 1990 C34. Even though we sleep forward
in the V-berth, we wanted to cool the aft cabin also for our
occasional overnight guests. We also wanted to preserve as much
storage space as possible since the C34 doesn’t ever seem to have
enough. After looking at several installations, we decided to put
the A/C unit under the V-berth and run a duct down the port side to
the aft cabin.
We selected a Mermaid 16,500 BTU side discharge air conditioner
because it was one of the smaller units available and Mermaid is
manufactured in nearby Fort Myers. The weight of the A/C unit far up
in the bow doesn’t seem to have made much difference in the
sailing of the boat, but we don’t race any more either.
glassed in a platform as high and as far forward under the
V-berth as the A/C would fit to preserve some storage in the
aft end of the compartment. I replaced the drawer unit with a
custom return air grill mounted on hinges to give easier
access, and it's worked out great. However, you do have to be
careful not to allow anything stored to stick up above the
grill to block the return air.
A/C is a side discharge unit mounted fore/aft on the platform
with the water pump right beside it on the platform. The
electrical control box is mounted on the same platform
opposite the water pump. The through hull is under the small
floor panel just to port and forward of the mast. Water
discharge is as high as possible under the V-berth on port
side near A/C, about 6" above the waterline.
the supply air, I used a "T" splitter directly aft
from the A/C with 6" to starboard and 4" to port.
The 6" goes through the forward hanging locker and up to
a 6" to 4x10" transition fitting from Home Depot
which connects to a 4x10" hole in the counter top above
the hanging locker. We can still hang clothes in front of the
6" duct. I built a teak plenum box about 5x12x12",
open on the back and bottom, that fits over the hole and
against the bulkhead.
is an 8x10" grill in the bulkhead opening into the main
cabin and a 4" round vent in the plenum opening into the
forward cabin. That takes care of the 6" side.
4" side from the A/C runs through the lower compartment
on the forward cabin port side,
the upper, outboard corner of the forward under settee storage
compartment in the main cabin,
the top, outboard corner of the holding tank to the open area
near the macerator pump.
used a length of 4" rigid aluminum duct to span the area
under the chart table since it was likely to get kicked. It is
wrapped in a piece of vinyl that matches the hull liner color
and is not very noticeable.
switched back to 4" flex duct in the aft hanging locker
(there were already slide out baskets in this locker - see the
for nav. closet project)
used a "Y" to split off a 4" round vent over
the chart table into the main cabin. I also mounted the
thermostat over the chart table but away from the vent.
biggest problem was cutting holes for the 4" duct down
the port side. I borrowed a 90 degree 1/2" drill and hole
saw and cut 4 1/4" holes in all the bulkheads down the
port side before I found that 4" duct needed a 4
1/2" hole to fit. I was able to enlarge each hole, but it
wasn't easy. I guess I should have tried the duct through a
test hole before drilling. Surprisingly, the 6” duct fit
through a 6” hole.
other side of the "Y" behind the chart table
continues out the aft side of the hanging locker behind the
hull liner in the head. If you remove the compartment where
the toilet paper holder is, you can get access to this area. I
used another "Y" to split off a 4" round duct
in the head and continued the other side to the aft cabin.
4" round duct in the aft cabin is in the top, port corner
of the forward bulkhead behind the head sink.
I can adjust the dampers in the vents over the chart table and in
the head to direct more or less air to the aft cabin. We sleep
forward in the V-berth, so the aft cabin is usually used for storage
unless we have guests on board. I used rubber pads to isolate the
A/C from the mounting platform and the platform from the hull, so
the noise and vibration in the V-berth is only a mild hum. It has
not been a problem sleeping.
I was able to find a 15A breaker that matches the other AC
breakers in the electrical panel and wired the A/C to that.
Everything runs on the original, 30A shore power. I looked at
Mermaid's Condensator to siphon the condensate overboard, but it
looked to me like seawater could come back into the boat through it.
Since my drain is pretty far up in the bow and gets hit by waves
when underway, I decided not to use it and I ran a drain tube back
to the bilge sump in front of the mast. I usually have a little
water in the sump anyway because of the keel-stepped mast.
We have been very pleased with the A/C performance. If we have
guests on board, we partially close the chart table and head vents
and the aft cabin cools nicely. We used a reverse cycle unit and we
even took advantage of the heat a couple of times this winter. The
hinge down return air grill to give easy access to the remaining
under the V-berth storage was an added bonus. With cool air ducted
to every cabin and minimal impact on storage space, we’re more
than happy with the results.
and Terry Clark
Yet To Be #1095
Important: The opinions expressed here are those of the
individual contributors to this page, and not those of the Catalina
34 National Association or Catalina Yachts, Inc. Additionally, this
material has not been reviewed by Catalina Yachts, Inc. for
technical accuracy. This page's maintainer cannot guarantee the
accuracy of this information or the desirability of suggested
modifications or upgrades. Please obtain assistance from a competent
marine mechanic or boatyard prior to making any significant
modifications to your vessel.