Air Conditioning - $300....?

Jim26m

.
Apr 3, 2019
579
Macgregor 26M Mobile AL
Hmmm... Our air conditioning on Lake Erie is anchoring out, and opening the forward hatch over the v-berth. We also rig a custom made canvas cover over our boom to shade the cockpit and cabin.

on the hot summer days, lake water is usually in the low 70’s. This water is passively cooling the hull. Then, the air on the water’s surface is cooled near the water temp. So the breezes that come in the hatch provide substantial cooling. A scoop over the hatch cover accelerates the breeze. The combined effect means we are seldom uncomfortable, even on a 90 degree day. Getting away from the hot, humid shore breeze and into the Lake Erie Island anchorages also helps.
Sounds lovely! Now is the only season we can enjoy that type of cooling.
 

Jim26m

.
Apr 3, 2019
579
Macgregor 26M Mobile AL
@Manete,

What are your expectations for this project? Low 70's in the boat on a 95 degree, high humidity day; zero noise; uniform temps throughout the boat; and imperceptible air movement? If so, stop now.

Using portables, or window units, if done properly, can give you relief from the heat and humidity, but won't do it uniformly or silently. But, I've been in some nice hotels that might as well have had window units in them, and it didn't make me want to sleep outside on a bench. As pointed out by @TimFromLI , @Justin_NSA , and @Tally Ho , pretty good results can be achieved. Shading and sealing up major air infiltration points, combined with doing a decent install may give you what you're looking for - providing your expectations are not unrealistic. As you said, "How much can go wrong here"?

Good luck, post pics, and tell us how wonderful it is to sleep on your boat without having to marinate in your own juices...
 
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Likes: Justin_NSA
Feb 4, 2006
16
- - Webster, NY
I tried to use one of the AC units with a hose on my Catalina 28 one year. One night when it was 90F and humid we turned it on. In the middle of the night I woke to a mist of water in the aft berth. The condensation on the cooling element was dripping onto the fan and shooting water into the cabin. It soaked the floor. And in the process the water on the plastic squirrel fan broke a blade and it made a horrible noise. These units were designed to be level. I tried to make it so on the unlevel cabin floor, but obviously when my wife and I were in the aft cabin the bow raised and the condensation ran forward in the unit instead of backward to evaporate on the hot side of the condenser as it was designed to operate. I repaired the squirrel fan and gave the unit away.

Instead I went with a small window AC unit sitting on the foredeck just forward of the V-berth hatch. I have a wooden shim at the forward end to level it approximately, but if the condensation does drip, it will be on the foredeck not in the cabin. I made a shroud out of Sunbrella to keep the part that is normally inside the windows out of the weather. I used Velcro around the V-berth hatch to make it water tight. When I tried it, I found that there was too much mixing of the incoming hot air and outgoing cold air through the V-berth door. I made a fabric piece that attaches to the AC unit between the air intake section and the outflow section and led it half way high through the V-berth door. It seems to do a good job of cooling the main cabin. The V-berth is still usable, but the fabric chute makes it harder to crawl in and out (although you can detach it and reattach it). The AC unit is small enough to lift through the V-berth hatch, and I normally store it on the side of the V-berth when we aren't using it.

After all is said and done, I would prefer a proper marine AC installation, but I don't use the AC enough to justify it.
 

Manete

.
Feb 5, 2020
16
Catalina 30 MKIII Middle River
I tried to use one of the AC units with a hose on my Catalina 28 one year. One night when it was 90F and humid we turned it on. In the middle of the night I woke to a mist of water in the aft berth. The condensation on the cooling element was dripping onto the fan and shooting water into the cabin. It soaked the floor. And in the process the water on the plastic squirrel fan broke a blade and it made a horrible noise. These units were designed to be level. I tried to make it so on the unlevel cabin floor, but obviously when my wife and I were in the aft cabin the bow raised and the condensation ran forward in the unit instead of backward to evaporate on the hot side of the condenser as it was designed to operate. I repaired the squirrel fan and gave the unit away.

Instead I went with a small window AC unit sitting on the foredeck just forward of the V-berth hatch. I have a wooden shim at the forward end to level it approximately, but if the condensation does drip, it will be on the foredeck not in the cabin. I made a shroud out of Sunbrella to keep the part that is normally inside the windows out of the weather. I used Velcro around the V-berth hatch to make it water tight. When I tried it, I found that there was too much mixing of the incoming hot air and outgoing cold air through the V-berth door. I made a fabric piece that attaches to the AC unit between the air intake section and the outflow section and led it half way high through the V-berth door. It seems to do a good job of cooling the main cabin. The V-berth is still usable, but the fabric chute makes it harder to crawl in and out (although you can detach it and reattach it). The AC unit is small enough to lift through the V-berth hatch, and I normally store it on the side of the V-berth when we aren't using it.

After all is said and done, I would prefer a proper marine AC installation, but I don't use the AC enough to justify it.
I agree - I think I’m leaning on waiting to install a proper marine AC.
 
Nov 23, 2015
10
Catalina 30 Stockton Missouri
I am struggling with the same A/C issues. Last summer/fall was miserable as the outside temp often hit 95 -100 degrees (Stockton MO) in my cockpit setting in the slip. I conferred with the local marine service people and it was suggested that the best option would be a 16500 btu marine unit, placed either under the V-berth (removing the 17 gal. freshwater tank) or in the hanging locker just aft of the V-berth. The cost estimate was between $5000 -6000 installed. Both options were somewhat problematic as they would reduce the utility of these spaces. Then again not sailing for several months during the summer and first half of the fall would also be a problem. I have a 1983 Catalina 30, so even though she is in pretty good shape, I am skeptical that the investment would increase the resale value by anywhere near that amount. It is nice to read that others are also grappling with these issues. Oh and to support the electrical supply issues posed by this large A/C unit I was informed that it would be necessary for an additional 30 amps service be added to my slip at my expense. The above comments are all very true and accurate. Especially as they relate to a Catalina 30.
 
May 7, 2011
205
Catalina 30 Lake Lanier
Marine A/Cs are more than 'portables', but imho they are vastly superior if you actually NEED A/C. If you are in northern climes they may do, but here in Atlanta they can't cut it when the air temp is near 100... We had tried a cruise-air portable unit and it did not do anything but drip condensate on us. Then we put a Webasto 24,000 110V a/c in. On the hottest day you could hang meat in the cabin, (Cool 20 degrees in 20 min.) but it was over-sized and would overshoot the target temp by 5 degrees due to minimum run times. We switched to a Webasto 16,000 unit last year. It takes about 3 hours to cool 20 degrees (92 to 72) but once there it can keep it all day/night if you keep the hatches closed.

I installed it myself. I moved the batteries from under the nav station and cut the bottom out of the battery tray. Ran ducts forward to hanging locker and v-berth, and another up and forward to middle of starboard shelf. Had to drill a few 4" holes and one 2"x 6" ellipse for the duct work. Built a platform and installed A/C under Nav Station. Since we can not discharge black water, I used the macerator thru-hull for the raw water intake. See my Pintrest page for more.
 

Jim26m

.
Apr 3, 2019
579
Macgregor 26M Mobile AL
Marine A/Cs are more than 'portables', but imho they are vastly superior if you actually NEED A/C. If you are in northern climes they may do, but here in Atlanta they can't cut it when the air temp is near 100... We had tried a cruise-air portable unit and it did not do anything but drip condensate on us. Then we put a Webasto 24,000 110V a/c in. On the hottest day you could hang meat in the cabin, (Cool 20 degrees in 20 min.) but it was over-sized and would overshoot the target temp by 5 degrees due to minimum run times. We switched to a Webasto 16,000 unit last year. It takes about 3 hours to cool 20 degrees (92 to 72) but once there it can keep it all day/night if you keep the hatches closed.

I installed it myself. I moved the batteries from under the nav station and cut the bottom out of the battery tray. Ran ducts forward to hanging locker and v-berth, and another up and forward to middle of starboard shelf. Had to drill a few 4" holes and one 2"x 6" ellipse for the duct work. Built a platform and installed A/C under Nav Station. Since we can not discharge black water, I used the macerator thru-hull for the raw water intake. See my Pintrest page for more.
First rule of ac install. Match the capacity to the load. Excellent discussion of first one is too small; second one is too large; and the third one is just right. Hate you had to do marine air systems twice, but sounds like you nailed it on the second go.

Enjoyed your other mods on your Pinterest page. You do good work!
 
Oct 29, 2012
346
Catalina 30 TRBS MkII Milwaukee
Hmmm... Our air conditioning on Lake Erie is anchoring out, and opening the forward hatch over the v-berth. We also rig a custom made canvas cover over our boom to shade the cockpit and cabin.

on the hot summer days, lake water is usually in the low 70’s. This water is passively cooling the hull. Then, the air on the water’s surface is cooled near the water temp. So the breezes that come in the hatch provide substantial cooling. A scoop over the hatch cover accelerates the breeze. The combined effect means we are seldom uncomfortable, even on a 90 degree day. Getting away from the hot, humid shore breeze and into the Lake Erie Island anchorages also helps.
With these last couple of days below Zero here in the Great Lakes, we welcome those couple of days in the 90's. Just sail east until there is no more off shore breeze.
 
Feb 2, 2014
29
Catalina 30 mkII Pasadena, MD
I have a 87 Catalina 30 and I also sail on the Chesapeake bay. I went down the road of a cheap widow air conditioner in the companion way (works well after the sun starts to go down and until maybe mid-morning). It was only a 500 BTU unit, so it wasn't too heavy, but still I was concern my wife would have difficulties moving it out of the way in an emergency (i.e. fire). So I went with this 12,000 BTU marine unit:

Webasto FCFK Air Conditioning Unit w/ Reverse-Cycle Heat - Complete System Kit

I installed it in front of the water tank in the forward v-birth. I built a small shelf and put some left over speaker mat on it to kill vibrations (the mat was left over from when my son built his sub-woofer enclosure for his car, the grey stuff). I ran one vent under the head's sink to the bulkhead on the port side of the settee and ran the other vent through the bottom of the hanging locker to the starboard side of the settee. I point the airflow a bit upward. To my surprise there is a slight breeze going into the v-birth, so I didn't add a small vent to it like I was planning to do. I sleep in the v-birth and the A/C is pretty quiet and doesn't wake me up. I put it in in 2016.

The shelf top is blow the top of the water tank to provide clearance for the top of the A/C unit.
20160619_143720.jpg


The A/C unit before I install the vent hose Y slitter and vent hose.
20160625_190949.jpg


The location of the vents (sorry for the blurriness). The air return vent replaces the teak access door for the front water tank cutoff valve (its slightly visible, its the extra white part below the teak step to the v-birth).
20160724_173941.jpg
 
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Sep 25, 2008
464
Catalina 30 MKIII Varuna Boat Club
I have the same model sitting in my storage room at the Club. It came with the first Cat30 I bought in 2008 and am now on my second Cat30 and have yet to use it. As hot as it can get in Brooklyn waters, as long as I'm moving, all is well. We do not "camp out" on the boat, so whenever we are aboard, we are moving. Anyway, I still don't know if it works?
I used a cruiseair-carry-on on my 32 foot Ericson and it did a great job They fit over a cabin hatch . Cooled the whole boat down. The only downside was it was a bit heavy . They don't make them anymore. I still have mine, I'll be selling it as soon as I get around to it, my current boat has A/C.
Here's a pic of one


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