Dehumidifiers

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BonesD

Senior Member
Joined
Apr 23, 2019
Messages
268
Location
USA
Vessel Name
Michelle
Vessel Make
1977 Schucker 436
Any favorite dehumidifiers y’all can recommend!
For about a 40 foot boat? Probably about 1500 cubic feet.
Thanks
 
We bought a Frigidaire off of Amazon, been running for about a year now with no issues. I was looking for something that worked in low temperatures, which probably won’t be a big concern for you. It’s noisy, but no more so than the last one we had.
 
I have two little GE units from Home Depot
 
I have two 35 pint units. One is a Whirlpool and the other I think is a Honeywell. I bought both of them at Home Depot or another big box store (at separate times).
I use one on the boat over the winter. It is operating on a timer for 12 hours per day, sitting on the galley counter. I attach a hose to the drain (so the 35 pint tank doesn't fill and stop the unit) and drain overboard through the galley sink. My boat is 40 feet overall with a 13 foot beam. With outside humidity ranging from 80-98% this keeps the humidity inside around 40-50%. I also have an oil pan heater on the single main engine (250 watt Wolverine brand), and this helps keep the entire ER warm and dry.
My second unit is used in the garage at home. I turn it on to control moisture when the car comes in soaking wet. It rains here a lot in the winter.
I am quite happy with both.
 
We have two of these: Frigidaire 30-Pint Dehumidifier... https://www.amazon.com/dp/B07QTY1XS5?ref=ppx_pop_mob_ap_share
running 24/7 for the last year. Depending on how much we open the boat to outside air they get emptied once a day to once every other day. They make a huge difference in livability below, irregardless of how they keep the mold away. Dryer is better.
 
Through trial and error we have possibly found the reason for nuisance trips on the Magnum inverter charger. The 30 pint Frigedaire de-humidifier, maybe. So a new and different brand will be purchased. We'll see.

Otherwise it works great.
 
One thing I do know is don't buy one of the low capacity- less than 2 pints a day, Peltier effect dehumidifiers. They don't have enough water removal capacity to keep up with air leakage in my small boat.


David
 
Just info, when a dehumidifier is rates at 35 pints, or 30 pints, that has nothing to do with the size of the condensate tank, it is how much that particular dehumidifier can remove from the atmosphere in IDEAL conditions in a 24 hour period. So a "35 pint" dehumidifier may only have an 8 pint (one gallon) sump, even though it is capable of removing almost NINE gallons of water in a day . . . They can only remove water vapor until the sump is full, unless you have the optional hose to drain overboard, or into bilge or black tank, etc. Best bet is to place on galley or head counter, and drain into sink. That way the condensate drains overboard as fast as it is removed from the atmosphere!
 
I have a 50 pint Danby that works well. I have it draining into the galley sink with a hose.
 
I think most of these are made in the same few Chinese factories.

There are some models that have a built in pump, that will empty the tank through a small tube when the level triggers it. I've got one (running in the beach house) and it works well. If the pump fails and tank gets full it will shut down. That might be very convenient on a boat.

I built a dehumidifier into the trawler using the AC ducts. Maybe the best mod I've done.
 
Returnable!
2 brands I tired (from AMAZ and HD) were not compatible with my marina's electric service. Both had electronic faults and shut off. Returned them.
Now use DampRid and like it. No moving parts!
 
Returnable!
2 brands I tired (from AMAZ and HD) were not compatible with my marina's electric service. Both had electronic faults and shut off. Returned them.
Now use DampRid and like it. No moving parts!

Damp-Rid gets pretty expensive after a year or two it also only pulls out about 1% of the water that a dehumidifier does. Electric dehumidifier uses power, but many marinas charge a flat fee for electricity and don’t meter. If you are transient like us you always pay by the day not the ah, so running extra units is free. Damp-rid is not, you pay again and again. If you buy Amazon warranty they replace them if they rust out, which hasn’t happened to us yet.
 
Thanks for all the helpful suggestions. Between the rain and snow I need something tgat works well.
Thanks again.
 
I recently decided to try a dehumidifier to reduce the humidity level in my boat and I am glad I did. In fact, I don't know how I managed on the boat before the dehumidifier, it is a night and day difference. As mentioned before, the small ones don't work for what you want/need. You need a "regular" one - i.e. 30 qt. I haven't had mine long enough to recommend it, but it does have some features worth noting when shopping for your dehumidifier. Adjustable humidistat - my boat is not kept where I live, so this was a necessity. I can set it at 50% and just let it run when it needs to. Drain hose - again I don't live near my boat, so I can't empty the water regularly. A nice benefit to the model I purchased is the drain hose attaches above the reservoir. So any drips are caught by the dehumidifier tank, which also has an auto shutoff float switch. Lastly, do check and see what temperature they are rated for. Mine for example works down to 38 degrees. One more note - I like you have a 40 or so foot boat and I was worried the 30 qt wouldn't be large enough. After using it I found that the air in the engine room as well as the other end of the boat is sufficiently dehumidified.
Cheeers.

My model for reference.

https://www.lowes.com/pd/Hisense-30-Pint-1-Speed-Dehumidifier-ENERGY-STAR/1000558837
 
Thank you. I will take a look.
 
Does a 30-35 quart dehumidifier keep the bilge inner hull condensation from forming?
 
Does a 30-35 quart dehumidifier keep the bilge inner hull condensation from forming?

As long as you can keep the dew point below hull temperature, you'll be able to avoid condensation. Most compressor dehumidifiers will struggle to get the dew point much below 34 - 35 degrees and just can't get it below 32 - 33.
 

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