A/C on all the time...

[scootdogg]

i was just curious on how many leave your AC on all the time even when not on the boat during the week. i am at my boat at least every other weekend but when i leave i turn the A/C off. i see other boats at the marina that are constantly running it... is there some benefit that i am missing?

 

[Groucho]

I don't leaver the AC on per se...But I do use the humidity setting. It cycles the fan and compressor a few times a day and keeps the moisture to a low level. I can't see keeping it cool for that long unless you are in it.

 

[HUMPH]

I leave a small fan running in the cabin just to circulate air so it's not so stale. Seems to work pretty well. We are in a covered berth so it may be different if we were in an open slip...

 

[SeaNile]

I'm too chicken to do so. I shut everything off before I leave the boat, only thing on is a refrigerator and the battery charger.

 

[Cincy Aquaholic]

Humidity setting as well.

 

[DaleM]

humidity setting here.

 

[tbirdvet]

I'm too chicken to do so. I shut everything off before I leave the boat, only thing on is a refrigerator and the battery charger.

Same here. It only takes a few minutes to cool down the cabin when I return so why leave it running?

 

[mquiet]

I set temp to 75 degrees and leave on. I do not think I have a humidity setting (wish I did). Mostly it runs the fan, but it will keep the moisture out during the week and deep mold and mildew growth to a minimum. I see quite a few boats at our marina do the same. I am in the Northeast and we only use our boat for 4 months a year and then store, so not running A/C all year.

 

[RollerCoastr]

I do not think I have a humidity setting (wish I did).

You probably do. If you have CruiseAir SMX controls, they have all sorts of user adjustments, but because it's not intiutive, many owners don't know about them. The "dehimidify" function on a SMX is activated by simultaniously pressing "HEAT", "COOL" & "FAN". The display will blink: "HU"

Other useful adjustments of the older SMX's include the dimming of the display LED's, adjustment of fan speed (to make low even lower for example), calibration of the thermostat and changing of the runtime and duration of compressor cycles in HU mode.

MarineAir also produced control pads that offered a dehumification mode without a specifically labeled key.

MarineAir refers to the dehumidification mode as "moisture mode". Moisture Mode in the older digital controllers is activated while the unit is ON. Simultaneously press the PWR and the DOWN button.

Older digital MarinaAir units are also programmable.

Manuals for CruiseAir and MarineAir units can be found on the Dometic website.

 

[copb8tx]

I just learned 2 weeks ago about the dehumidify settings on the SMX. I'm anxious to get to the boat this weekend and see how it worked.

Usually I just let the thing bake in 100+ heat and turn the units on when we first arrive. It's hours before it's back down to anything comfortable. I was always hesitant to leave the AC while I'm away because in this heat the compressors would run non-stop.

 

[jason78]

I turn mine up to 82 and leave it on. It really does not too run much but it keeps the cabin from sitting there in the heat all day every day. There are so many things in the cabin held together by adhesives, I just don't think the boat sitting all day at 100+ degrees day after day can be good for everything in the cabin. I think the humidity program only runs for something like 30 minutes every 12 or 24 hours which is not enough to keep down the humidity in my climate, in my opinion.

 

[Sum Escape]

I turn mine up to 82 and leave it on. It really does not too run much but it keeps the cabin from sitting there in the heat all day every day. There are so many things in the cabin held together by adhesives, I just don't think the boat sitting all day at 100+ degrees day after day can be good for everything in the cabin. I think the humidity program only runs for something like 30 minutes every 12 or 24 hours which is not enough to keep down the humidity in my climate, in my opinion.

You can also set the intervals between "humidity control" cycles so it runs more often.

 

[Dave S]

I leave mine on all the time with the temperature bumped up to 80. I probably wouldn't run it if I lived in a more temperate climate but in hot humid summer climates like ours, we are constantly above 90 degrees with high humidity to boot.

Dave

 

[Southpaw II]

I leave mine on 24/7, but move the thermostat up to about 80 when I'm gone. I lost a refrigerator years ago on a 290DA due to overheating in the cabin, I think, so I don't want that to happen again. The humidity setting just doesn't seem to do it for me.


Don

 

[Alex F]

I was debating on what would be the best approach when I got my 320DA. The biggest issue I had leaving the A/C on set to 80-82deg. is that the fan stays on all the time while the compressor takes periodical break. The "HU" mode runs the system for about 30min and then shuts it down, including the fan. I don't feel comfortable having the fan running non-stop, so my choice was "HU" mode. Sure the temps raise somewhat higher than if the unit was in A/C mode set at 82deg., but it's still keeps the salon in reasonable state and I know that the air gets circulated.

 

[jason78]

I was debating on what would be the best approach when I got my 320DA. The biggest issue I had leaving the A/C on set to 80-82deg. is that the fan stays on all the time while the compressor takes periodical break. The "HU" mode runs the system for about 30min and then shuts it down, including the fan. I don't feel comfortable having the fan running non-stop, so my choice was "HU" mode. Sure the temps raise somewhat higher than if the unit was in A/C mode set at 82deg., but it's still keeps the salon in reasonable state and I know that the air gets circulated.

You can set the fan to where it only runs when the compressor runs. That was the first thing I changed when I bought my boat. That fan running constantly was down right annoying.

 

[Alex F]

You can set the fan to where it only runs when the compressor runs. That was the first thing I changed when I bought my boat. That fan running constantly was down right annoying.

I didn't know you can do that. Can you share the steps (I don't recall seeing them in the manual, but if they're there I'll look again)?

 

[jason78]

I didn't know you can do that. Can you share the steps (I don't recall seeing them in the manual, but if they're there I'll look again)?

I assuming you have the SMXir Control Pad

Fan Mode
(Factory Default: Continuous)
You can select continuous fan operation or instruct the fan
to cycle on and off with the setpoint.
To select continuous or intermittent fan:
• Enter the programming mode: Press OFF, Press SET
• Press DOWN, FAN and UP simultaneously.
• Use the UP or DOWN key to select C (continuous) or
I (intermittent).​

• Press OFF to exit the programming mode.


Full manual is available here- http://tinyurl.com/3gewmwe

****Make sure you refer to this manual when making changes. You will notice there is a Revision Date of 7/05 on this manual. My paper manual was printed before this revision date and has several typos or ommissions. I thought my system controller was bad until I discovered my manual was bad and the new manual was corrected. Now I have had no problems programming it with the updated manual.

 

[jason78]

You can also set the intervals between "humidity control" cycles so it runs more often.

Agreed.

Programming The Time Period
(Factory Default: 12 hours)
The time period determines how often the system performs
the dehumidification process. You can select intervals of 2,
4, 6, 8, 10, 12, 14 or 16 hours. Chose a shorter time period
in climates with high humidity.
To select time period:
• Enter the programming mode: Press OFF, Press SET
• Press TEMP and UP simultaneously. The display will
show the overall time period in hours.
• Use the UP or DOWN key to select the desired time
period.​

• Press OFF to exit the programming mode.

With the humidity we have around here, I am not sure if even the lowest interval of 2 hours would be enough.

 

[Pietro]

For you leaving the A/C on all the time, aren't you afraid that a hose could pop off allowing the sea water pump to sink your beloved boat????