405/406 air conditioning

[Mystic144]

The boat I am looking at has 2/16000BTU AC units
My question is this enough to cool the forward cabin,main cabin and the aft cabin during the really HOT SUMMER days???

[Lyndon670]

Its never a problem to cool the aft cabin or forward cabin. You just close the cabin doors. Because there is no windows beyon tiny portligts and that they are at water level, they will cool quickly and stay cool. The main salon will be your issue. Keep the blinds closed and get front window covers and you will be fine.

[Viper]

Interesting that there are only 2 units. Is this common for a 405? Ambient cabin temps are a large factor and as Lyndon said, if you have the sun shining in, it'll make it that much more difficult to bring temps down.

[dsolo]

My 1997 405 has 3 AC units. One 16K btu located in the salon, a 9K btu located in the aft stateroom, and a 6K unit in the forward stateroom. I have no experience with their performance or ability to keep the vessel cool??. I purchased the boat in late October. See me in July/August.

[Viper]

Source of the post My 1997 405 has 3 AC units....

The number of units was either an option or perhaps one was removed and never replaced? Perhaps Kenny remembers Carver's offerings for the model.

[g36]

heres my expereience i have a 405 and live in tennessee mid to upper 90s and lots of humidity and many nites in the 80's in the summer and i can tell you that the 2 ac units will not be enough to sleep comfortably . the salon and small forward stateroom are no problem i did alter the orignal design a bit but because the way the 405 has it the forward ac unit dumps air into both places fwd and salon areas the problem actually is the aft cabin. my 405 has one rectangular vent over the port side locker fed from the salon and it does marginal job for day time but trying to sleep forget it even with the door open and a fan blowing air in the door to help cool it theres just not enough air flow to the space .the electrical panel was ready for 3 but the boat was only orginally equipped with 2. relocated the thermostat to the salon where it should be and i added a mermaid 5200 ac/heat to the aft cabin and it handles the temp fine no problems. close the door while sleeping now and thermostat will control that zone and you wont have to try and keep the rest of the boat like a meat locker to get the aft cabin cool. youll be much happier with 3 unit imo

[Mystic144]

Thanks for the input
Where in the aft cabin would you locate another AC unit?

[dsolo]

The aft AC unit in my boat is located under the bed platform. It is the 9k btu unit. There is a thermostat in the room.

I am somewhat concerned about the salon AC unit. It draws make up air from a grill located perpendicular to the coil intake. The coil is right up against a salon wall. The wall is behind the salon sofa. There might be a 3/4" between the wall and the air flow for the coils? I found the coil and cooling fins covered with dust and carpet lint.
The fan is trying to pull air through the perpendicular grill opening and the 3/4" narrow space. I am considering opening the wall behind the sofa and having the air drawn directly onto the coil. The sofa may need to come away from the wall an inch or two. I need to see how things work this summer. Lots to review.

[Mystic144]

Hi dsolo
Thanks for your comment on the location of the aft stateroom AC. Makes perfect sense for the aft cabin to have it's own unit.
As for the salon unit with the air feed behind the couch just does not seem that the unit is getting enough air supply. Without adequate air the unit can not operate as designed.
Please let me know what you do to rectify this.
Thanks
Rene

[tomschauer]

My 355 is a bit smaller than your 405. I have a 16k unit that serves the salon and forward state room and a 12k unit that serves the aft cabin and also has diffuser serving the salon. During 90 or 90+ sunny days I will loose some ground and it may hit 75-77 in the salon, but as soon as the sun drops, I could hang meat anywhere in the boat if I wanted to set it low enough (wife keeps it at 68). I did remove both units and properly clean the coils when I bought the boat. Dirty coils and fans will reduce capacity significantly. It is nearly impossible to properly clean these coils in place if they have been allowed to be packed with dirt and dust. Just brushing the surface will not do it!!!!
Before adding a unit, or changing the ducting, I would make sure the coils are clean, the unit(s) are properly charged and they are working at full capacity.