De-Humidify mode on cruiseair

[Turtlesboat]

I just found out about this mode on my AC. Hit cool/heat/fan and it puts the unit in a de-humidify mode. I'm trying it out for the next 3 days. It's hot as hell and humidity is crazy. Does anyone else use this mode on their boat?

 

[downeast320]

not much humidity in maine but, i was under the impression that running the ac also dehumidified at the same time. Am I way off base here?

 

[Dave S]

I set my Air Conditioner at 79 degrees instead. High temperatures are not good for your refrigerator if you leave it operating. In fact Norcold advises specifically against running the refrigerator in high cabin temperatures. Since my fridge is also running when I am away from the boat, I figure running the AC is better than putting it in dehumidify mode which would probably not maintain a very cool temperature.

BTW.............unless you have an AC/Heating vent in your Head, don't forget to leave the Head door open as well so it dehumidifies or cools that area.

 

[jg300da]

I use the dehumidify mode whenever we're away from the boat. Works great and keeps the cabin fairly cool.

 

[Asureyez]

De Humidifying

You, that is a tremendous feature for boats that ar ein Florida. When boats are closed up, haot and dark inside ... the result is mildew voracious mildew. That stuff can make aboat un inhabitable.

I leave the airconditioers (two) on the Dehumidify setting all year round. The units will only kick on the pump to draw sea water as needed, but will circulate the air at a slow speed 24/7.

This feature is great.

 

[osd9]

I just found out about this mode on my AC. Hit cool/heat/fan and it puts the unit in a de-humidify mode. I'm trying it out for the next 3 days. It's hot as hell and humidity is crazy. Does anyone else use this mode on their boat?

Do you hit all three buttons at the same time and do the fans go into a auto speed mode????

I generally leave everything off and only turn on the AC when it gets REAL hot...(like yesterday and today....AC on.... set to 78). However, I probably should start to use the De-H feature... :smt017

I could just go home and read the manual ( I will anyway) but it's always nice to get real world experiences and advise from those in the know....

thanks,

 

[Hampton]

The DH mode runs the A/C periodically instead of constantly. The A/C does DH the air, both in A/C and DH. When the air is instantly cooled, the water vapor can no longer be held, so it falls out (condensation, rain...). It falls to the bottom of the A/C unit and runs out through a drain tube.

Even if you have a vent in the head, leave the door open (unless you have a return in there, which I doubt). Circulation is a two-way street. Even with forced air in, if the door seals up relatively well, then air can't escape, so it's like blocking the A/C vent.

 

[comsnark]

High temperatures are not good for your refrigerator if you leave it operating. In fact Norcold advises specifically against running the refrigerator in high cabin temperatures.

That is hilarious.

A refrigerator works on the same principle as an air conditioner, which in turn is conceptually similar to a heat pump.

What Norcold is saying is that they can only cool the refrigerator "x" degrees below ambient temperature. Say, 60F. So if your cabin climbes to 110F, the darn inside of the refrigerator will be 50F.

So you are in essence putting a small refrigerator inside a big refrigerator (your boat A/C) to keep it running well.

I suspect this is another case where running a few fans to keep air movement through the boat would be the best answer. (keeps mildew down, keeps CO down, keeps heat levels down)

 

[Dave S]

For the record, this is what the manual says.

Over Heating Shut-off Device Operation (DE0240T & DE0251T)
Operating the refrigerator in high ambient temperatures can over heat the cooling unit and
cause premature failure of the compressor. (See the label inside the refrigerator.)
To protect the cooling unit from over heating, the refrigerator will automatically shut-off when
the vehicle air temperature is higher than approximately 130° F. If shut off occurs, an
audible alarm tone (an intermittent beeping) operates from the refrigerator.
To stop the audible alarm tone and restart the refrigerator, turn the thermostat counterclockwise
to the “OFF†position and then clockwise to the desired thermostat position.
The refrigerator will not restart until the air temperature is lower than approximately
130° F.[/b]

I doubt it will ever get to 130 degrees but the refrigerator will work harder the hotter it gets. And since Norcolds are not known for their long life, I just want to make sure mine lasts as long as possible,

Incidentally, what type of interior temperatures are maintained when running in the de-humdfy mode?

 

[Turtlesboat]

Yes you press all three at the same time, at least on mine you do. I imagine yours is the same. Actually if you open up the little door on the control panel, there should be directions on how to activate it. Not sure how cool it keeps the cabin yet as I just turned it on last night. But in the short time I had it on before I left, it was cooler and dryer than outside. It cycles so it's not running more than it needs to. Glad others think it works great. Last thing I need is mildew cropping up.

 

[gerryb]

I have used the DEH cycle ever since I discovered it on the little pamphlet that sits inside the AC Control cover..(Actually someone mentioned it in the SRO but I didn't get it then.) This is a special cycle that serves to circulate air and remove some of the humidity from the cabin. It runs a Fan Only mode, then AC MODe, each 10-15 minutes, every 12 hours. I can tell you it works very well and is energy efficient. (I pay for my electric in the slip). IMO, this cycle is better than just running the AC because it is programmed to run the FAN at HIGH Setting. Leaving the unit in the normal AC mode, at a set temp, will probably never run the fan at the HIGH setting, therefore you never get the highest degree of air circulation in the cabin. I only use the normal AC mode on the weekends when I'm at the boat. The DEH is a gem of a feature and I recommend it to anyone that uses a boat during the summer anywhere from Maine, south.

Re the NORCOLD thing, my cabin never gets over 85-90 degrees. 130 would be almost impossible to imagine...

 

[Hampton]

What about the cockpit frig? I bet that thing gets smokin'.

DH mode will keep each boat a different temp, and any one boat a diff temp on any given day depending on sun angle, clouds, outside air temp, wind, rain... It just cycles the A/C and fan on a set schedule regardless of OAT.

 

[Hampton]

P.S. - My A/C fan is the quietest on "High". It vibrates a little more and more the slower it gets. It's noticably quieter on high.

Anyone else? Sorry about thread creap.

 

[jg300da]

Read the manual that comes with the AC unit. The dehumidification mode is adjustable. You can control length of compressor run time and run frequency as well as fan delay settings. The factory default setting may not work for your area.

 

[osd9]

I just read the manual online....it says that you can program the cycle time different from the factory settings. In the De-H mode, the factory cycles the unit every 12 hours. Does everyone else just leave that setting? It just seems that 2 times a day for 10 minutes wouldn't be enough.... :smt017

 

[Dave S]

Here's my logic for using just the AC cycle.

First is the refrigerator issue.............Norcolds die way too soon from what I have read so hopefully this extends the life of the unit.

Second....why not keep the cabin a bit cooler all the time not just when you are on the boat. There is a lot of "stuff" in my cabin and if the cabin stays at 78-80 degrees everything will stay in better shape.

Then there is the humidity level itself. I was at the boat today and I have a thermometer with a humidity readout. Outside the humidty is very high......around 90 percent. Iinside the humidty was 48 percent. I doubt that the dehumidify function on the AC can maintain that low of a setting unless you change the factory setting.

And as near as I can tell my unit runs about every 10 minutes or so in this kind of weather.

 

[goblue]

We turn everything off including the fridge. It does get quite hot down below when we open things up and turn on the a/c. Maybe Michigan is different. It does get hot but dew points in the 60s are not that common. I believe that saves us from the mildew problem. We only use the fridge in late June to early August when we live on the boat. After that, it's clean the fridge very thouroughly, let it dry and turn off the a/c unless we are staying on the boat for a week end. Works for us.....no mildew. BTW, lots of people with cottages turn the heat up to 80 degrees for a couple of weeks in November to dry them out prior to closing them for the winter. They claim it helps get rid of the "cottage smell." Around here, I believe hot cabin temps keep boats smelling good as well.

 

[Turtlesboat]

My fear is that if I left the A/C on and the boat unattended for days at a time, a plastic bag or grass or something could float by and get sucked up into the water intake. With the dehumidify cycle, there's much less of a chance of that happening and it will only run for 10 min at a time if it does. Maybe i'm niave?

 

[Converse48]

My fear is that if I left the A/C on and the boat unattended for days at a time, a plastic bag or grass or something could float by and get sucked up into the water intake. With the dehumidify cycle, there's much less of a chance of that happening and it will only run for 10 min at a time if it does. Maybe i'm niave?

That's a good point, turtle! Plus my marina charges $60/month for the line item "Running A/C during the week". Dehumidify mode does not seem to trigger this charge. And yes, they actually do walk around and take note of how often who is spitting out A/C water. Strange but true.

 

[Stray Cat]

P.S. - My A/C fan is the quietest on "High". It vibrates a little more and more the slower it gets. It's noticably quieter on high.

Anyone else?

Ditto on fan speed

Great topic Turtle :thumbsup: Under a covered slip the cabin is cooler than outdoor temp after being shut all week. The humiditiy however varies significantly here. I presume the unit would shut down if an error code (over temp) occured due to a plugged or obstructed strainer... :smt017