Air Conditioning

Chip · Post by **Chip** » Sun Aug 28, 2016 3:25 pm

I have a 1986 33 SF and the original AC was on the fritz. I called MarineAir and they sent me to their local franchise holder. After some shopping, I went with him. He replaced the entire unit, new thermostat and softstart. This was done in March before the summer (I am in Florida). The problem is that it hardly cools the boat below 80. I put a temperature gun on the exhaust and compared it to the intake, and the difference was only about 10 degrees. I read on the Marineair website that it should be 15 to 20 degrees. My AC guy blew it off and said that is the best I will get in an old boat. I checked the exhaust in the forward vBerth, and there was a 15 degree differential there, but only 10 degrees in the salon. I paid a lot for the system, and the wife is not happy with it at all (and I am not satisfied either, but her discontent makes it even more acute). Any experience with this? I am wondering if he shorted me on coolant. Why would the forward berth cool 50% better than the salon? And the salon vent only blows cold air on about a third of the vent; the temperature at the other end of the vent is more like room temperature. Any thoughts would be appreciated. Ready to get a second opinion. Thanks.

buzzk · Post by **buzzk** » Sun Aug 28, 2016 4:08 pm

I have a FBC which has more glass than a Sport Fish and I can keep my temperatures in the 72 range at my dock. I live on a saltwater creek and the water temps get into the 90's and this summer has been extremely hot with air temperature highs in the mid to upper 90's. Out in the ocean or sound it's not a problem keeping the boat cool while fishing even with everyone going in and out of the cabin. What's the water temperature where you're keeping your boat? What size A/C did he sell you? I have to clean my sea trainer every month and add a couple of bromine tablets in the strainer to kill anything growing in my lines. I added a cover over the forward hatch, cutting the hatch light out really helped. I also added the sun screens on the outside of the front cabin windows. I forgot what you call them but it's on a lot of boats.

asher · Post by **asher** » Sun Aug 28, 2016 6:58 pm

Did he install a self contained unit or did he just replace the condensing unit on a split unit system? Also, what size unit was installed? My 35' has a 12k for the salon and a 4K for the v-berth and when both units are on the cabin cools off very nicely. I also have the v-berth hatch blacked out and a vinyl sun cover/bra for the front windows of the salon.

Capn Tony · Post by **Capn Tony** » Mon Aug 29, 2016 3:58 am

My A/C died last year. I replaced it with another Cruise Air and had a local tech install it. I don't recall what size it is but I remember it was the same as the one he took out; I want to say 16K. I bought the until from a distributor out of FL. Both my cabin and V birth chill to meat hanging temps even when the outside temps are in the mid 80's. Thanks Capn' T 33'Bert SF 3116 Cats Hyannis MA.

mikehedb · Post by **mikehedb** » Mon Aug 29, 2016 6:56 pm

In SW Florida the A/C is critical. I have to cover the window, routinely clean the strainer. I have a single 16K BTU unit and I have notice that the vent that I added in the salon has airflow that is several degree warmer. I believe it is because that vent hose is not insulated like the others and it runs along the hull where it probably picks up a little heat. It gets plenty cold at night but struggles to stay in the 70's during the afternoon when outside temps are in the mid 90's and the water temp is in the high 80's.

Rick · Post by **Rick** » Tue Aug 30, 2016 4:46 am

Not to get off subject, but there's a guy on my dock saying that if you put a small piece of copper tubing in your A/C sea strainer, it will keep it clean for the whole Summer. Guess he learned from someone in Florida. He just checked the other day, and he runs his 24/7, strainer is clean as a whistle. I shut mine off when I leave....scared it burn the whole boat down or fill it up with water. But I agree with Tony, even with Florida like temp's and humidity; our 16K units will freeze you out. Chip, have you verified that cabin vent is solidly fastened to the evaporator ? Maybe there's a hole in the vent tube ? Rick Ticket 85 SF Merc 454 MPI's Falmouth, MA

h2ojst · Post by **h2ojst** » Tue Aug 30, 2016 4:51 am

I also have 2 units down below. One in the salon & one in the V-Berth. When I lived in Ft. Lauderdale I installed a product called V-Kool on all the glass. Unlike regular tint (Which I had previously)it does not act like a radiator collecting heat & then transferring that heat into the cabin. The product really works and it reflects the UV (heat) away. After that was installed, even if the water in my canal was 90, I was able to run the A/c at the slowest blower speed and raise the thermostat several notches off the coldest setting to be comfortable. I still have the old 3 knob controls & not digital. Check out: http://v-kool-usa.com/ Call Scott Frischhertz & tell him that I referred you. 954-761-8463 He's the Florida rep. & does numerous yacht installations.

Chip · Post by **Chip** » Fri Sep 02, 2016 3:18 pm

Thanks to all of you for your comments. I have a second opinion guy going out to test it. He told me that it is not uncommon when flushing the unit for the unit, upon recharging, to appear full when in fact the coolant has not permeated through the system. He says you have to go back in a couple of days and top it off. I am hoping that is it. I will let you know. For thoe who asked, the unit is 16k, as was the one replaced. And he replaced everything except the copper tubing connecting the components. I am also going to try the windows treatment discussed. Great idea. Thanks again to all of you. Chip

Chip · Post by **Chip** » Tue Sep 20, 2016 5:29 pm

Thanks again to all of you for your help on my AC. I have more information. My second opinion guy came out last week, about 3 weeks after he said he would. I know he is busy, so I am forgiving on that. In any event, after a follow up email, he wrote back tyeh next day that he visited the boat, it was a new system, used new 410 gas, and that he checked the charge and it was fine (pardon run on sentence). He said he looked at it generally and it looked to be installed properly. I was not happy with the report, so Saturday I set out for the boat armed with a Milwaukee laser temperature gun and also a Klein Multimeter with a temperature probe. Beginning at about noon, I ran the system down to 65, the lowest setting, turn the fan on high, and then tested the exhaust and intake vents in the salon and the vberth. The system is a 16k system with a 12 kw evaporator for the salon and a 4kw evaporator for the v berth. I tested all vents twice, once with the Milwaukee and again with the Klein. Then I recorded all the temperatures and the temperature outside on the deck. One I turned the temp down, I had a temp differential in the Salon of only 4 degrees. I waited about 30 minuters and tested again, giving the compresser time to rev up, and I tested again. Then it was about 6 degrees. Came back about 3 hours later, temp was down about 2 degrees in the cabin and he differential was only about.5 degrees. I did this every few hours until about 8 pm, came back Sunday at noon, repeated the same thing until about7:30pm. Average temp differential in the salon between intake and outtake vents was 5-6 degrees. In the V berth I got about 9-12 degrees. The only extraordinary thing (other than pathetic performance, well below the expected 20 degree delta) was at 7pm on Saturday after running the system full bore for 7 hours I could not lift the salon floor hatch to the bilge. Pried it up with a knife...there was such strong suction I broke one of the lift rings trying to pull it up. Came home, dropped all of this on an Excel spreadsheet, documented times, temps and comments, and on Monday called tech support at Dometic. The troubleshooter was nice, admitted something was wrong, ask for the number of my installer, and today installer called back. He went to boat, confirmed It ws underperforming and said it was low on gas. His diagnosis was that the pressure couplings on the copper connectors were leaking. He is going back on Friday to solder all of them on, pressure test it with nitrogen at 150psi over teh weekend and, if no leaks, regas it on Monday. All that for a new 410a system that cost over 7k. Given the high pressure nature of the new systems, I am a little puzzled why he did not solder them on to begin with..the guys that do my AC for my properties advise that, but what can I say. So that's the status. I will let you know what happens when it is recharged. Thanks again for your comments. On another note, I am working toward painting the cockpit. The gel coat is pretty roughed up. Any of you done that? Maybe I will start a new top on it. Best regards.

asher · Post by **asher** » Wed Sep 21, 2016 9:24 am

Sounds like you are well on your way to becoming your own AC repair guy. All of the marine service companies around my area give the same treatment you are receiving. You have to give them hell to get them to show up, and if and when they do show up they will deny any responsibility with the system in question. Good luck in the next round of things and I hope you get better treatment from this point forward now that you have included some sort of corporate accountability.

Chip · Post by **Chip** » Tue Sep 27, 2016 6:16 pm

AC installer advised that the copper connections were sweat on last Friday. System was pressured to 200 psi over the weekend and held pressure. It was recharged on Monday. I checked it Monday evening and output temperature of air bottomed out at 57 degrees. Outside temperature was 78. Much better. He advised he would check it throughout the week and top off the gas if needed. So it looks like we have a solution. I understand that the 410 gas requires higher pressure to get the temperature down, and that requires more meticulous attention to connections, etc., to assure they can withstand the higher pressures. Thanks again for comments. Chip

Rick · Post by **Rick** » Wed Sep 28, 2016 2:52 am

Congrats Chip - you fixed it the way everything else gets done. Digging in and sticking with it. Rick Ticket 85 SF Merc 454 MPI's Falmouth, MA