# portable heater or de-humidifier?



## nightowle (Aug 2, 2006)

Now that it's getting colder here in Seattle, dampness is ready to set in. Am I better to get a heater or dehumidifier that I'll use on shore power in order to reduce mold, etc? I was thinking of using a Davis Air Dryer. http://shop.sailnet.com/product_info.php/products_id/39344?search=1&keywords=Davis
Right now I just have some of the 'pellet' products that pull some moisture from the air. I'd like to get some opinions on this subject.
Thanks


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## sailingdog (Mar 19, 2006)

Are you going to be using the boat, or living aboard the boat? If not, then the best way to get rid of humidity and prevent mold is to ventilate the boat well and to use a big package or several smaller ones of DampRid, or something similar. 

Electrical heaters are one of the biggest causes of fires on boats, and unless you're living aboard, or sailing the boat regularly, leaving a heater on long-term is a rather risky proposition IMHO.


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## thekeip (Aug 8, 2007)

I leave light bulbs on during cold winter nights...25w up fwd, and 40w in maim cabin....
Sometimes I use a 'Gold-Rod' under the engine and leave it on at night. It's rated 12w or so and seems to keep the bilge dry. I'm not sure it's doing anything, really, but make me more comfortable.
Howard Heiper
Sea Quest
Berkeley


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## Faster (Sep 13, 2005)

We use a small dehumidifier similar to the one you mention, and do notice the improvement inside the boat. However we were told to keep a little heat on too otherwise the cooling plate in the dehumidifier will freeze and it will stop working.

I check the boat regularly - twice a week at least, and leave the heater on "warm" rather than the hotter settings... keeps the boat at around 12 - 14C when it gets close to 0C outside. The reservoir in the dehumidifier gathers about half a liter(quart) in a week of soggy west coast weather.

Overall we're quite happy with this arrangement. SD is correct in the need for ventilation, so if security concerns allow, leaving a hatch cracked somewhere helps keep the air moving. We have also, in the past, hung a couple of computer "muffin" fans to move air around.


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## sailingdog (Mar 19, 2006)

The solar ventilators, like the Nicros, are pretty good at getting/keeping the air moving in and out as well.


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## Valiente (Jun 16, 2006)

A diesel bulkhead heater on low is surprisingly good at drawing the damp, inside air and sending it out the chimney. The key is circulation...if you draw in even damp air, your breath will make it damper still unless you can vent it positively out.

I have recommended the book "The Warm Dry Boat" before. As it was written by a guy living in B.C., its advice should be applicable.


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## TAK (Jul 14, 2003)

I was discussing this topic with a dock neighbor who has run 24/7 during the winter for several years a pair of West Marine portable heaters at the low setting (see below..)

They are a low profile so tipping over does not seem an issue and they have a switch that turns on if the temp falls below 38 degrees.

Was wondering if any one else has used them?

http://www.westmarine.com/webapp/wcs/stores/servlet/producte/10001/-1/10001/245831/377%20710%201664/0/Portable%20Heaters/Primary%20Search/mode%20matchallpartial/0/0&isLTokenURL=true&storeNum=5002&subdeptNum=12&classNum=743 )


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## JohnRPollard (Mar 26, 2007)

TAK said:


> I was discussing this topic with a dock neighbor who has run 24/7 during the winter for several years a pair of West Marine portable heaters at the low setting (see below..)
> 
> They are a low profile so tipping over does not seem an issue and they have a switch that turns on if the temp falls below 38 degrees.
> 
> Was wondering if any one else has used them?


We've been using that heater for about 8 years and have found it to be reliable. However, we only use it when we're aboard and attached to shore power -- I would worry about leaving any electric heater unattended for long periods. It does a fair job of taking the chill off in the cabin of our 31 footer, but not nearly as good a job as our Dickinson Newport P9000 propane fireplace.


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## dave6330 (Aug 16, 2006)

We just vent the boat with the solar vents and a mushroom vent on the forward hatch when we're not on board. The only thing running off of shore power when we're not "camping out" on board is the battery charger. We have one of the small electric heaters we use up front and an Espar forced air heater to keep things cozy when we're on the boat and (knock on wood), we've had no problems with dampness. When we leave the boat, we prop up the cushions from the v-berth (where we sleep) and open all the cupboards to allow venting. There's always water in the bilge, but we have a keel stepped mast and the couple of inches of bilge water is fresh, so I don't worry about it (much).


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## nightowle (Aug 2, 2006)

Good advice and suggestions so far. I am not sleeping on the boat and will use it infrequently during the winter, although I check on the boat about once a week. I have been keeping a 100 watt bulb on connected to shore power and have a couple of the small dry-eze tubs. I was thinking about also using a small fan I have to move the air, but was concerned about the safety of that.


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## TSOJOURNER (Dec 16, 1999)

West by North (.com) has little AC/DC dehumidifiers that will collect several cups of water in a weeks time. I keep one in my 34' boat, moored in Tacoma, and have to empty it once or twice a week. I don't know what West by North sells them for but I was able to find one elsewhere online for under $50. 

I also keep a low-profile Caframo heater running on low.

I installed a 110v "computer fan" under the v-berth so that it circulates air through the space between the hull and interior liner. I added 1" locker vents to various dead spaces to encourage circulation. This keeps all lockers dry. Pictures at sailingscamper dot blogspot dot com / search?q=ventilation. (You have to fix the link since I don't have post enough here to include links.)


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## Idiens (Jan 9, 2007)

I use a Honeywell compressor style de-humidifier. Since its rated at 280 W and runs about 50% of the time, it's like having both a heater and a de-humidifier. Works well too.


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## NorfolkRagbagger (Oct 3, 2006)

*West Marine 120V heaters*

I've used these for many years - they're efficient, safe, very flexible for temp (wattage) and blower speed. Used to use one in the engine room of a 50' trawler set to just above the no freeze zone - never a concern with safety. MUCH better value than to 1500W red Chinese heater cubes (West Marine model made in Canada) that last 60 days and lose heat output. Now use one in a V berth on low for cold nights in the winter in Norf**k, VA. _Nothing _better in the marketplace.



TAK said:


> I was discussing this topic with a dock neighbor who has run 24/7 during the winter for several years a pair of West Marine portable heaters at the low setting (see below..)
> 
> They are a low profile so tipping over does not seem an issue and they have a switch that turns on if the temp falls below 38 degrees.
> 
> Was wondering if any one else has used them?


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## TSOJOURNER (Dec 16, 1999)

About a month ago I went up my boat, and noticed all the under-decking in the forward compartment was not just damp, but had serious water and was dripping. I went to Second Wave ( a local secondhand marine store ) and bought one of those round West Marine dehumidifiers for $25 and set it up in the v-berth, went back the next day and it was bone dry.


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## Omatako (Sep 14, 2003)

Maybe an overkill when I hear about dehumidifiers for fifty bucks but we use a biggish DeLonge dehumidifier with low heat and it keeps the boat dry and warm. The unit we have has facility to drain the condensate directly into the bilge where it gets pumped over the side by an auto pump switch.


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## oft (Apr 25, 2006)

*Are troublelights an option?*

Well, I used a Caframo (looks very similar to the Westmarine unit) heater set to the antifreeze setting last year, but now Sailingdog has me concerned about the potential fire hazard ... which would probably result in a bit too much heat. People have mentioned leaving a bulb burning instead. What's the best approach to do this? Would hanging a troublelight (the metal screen surrounded fixtures attached to an extension cord) be a good option?


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## KeelHaulin (Mar 7, 2006)

Hmm... Now I am wondering why you would "vent" the boat (non-live aboard) rather than de-humidify the cabin air and not vent that air. It seems to me that if you de-humidify the existing air in the boat you will dry it out inside by sucking the moisture out of the interior air. If you ventilate while de-humidifying it would be like leaving your freezer door open and expecting the ice to stay frozen, correct?


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## HoffaLives (Feb 19, 2007)

I would doubt that a dehumidifier that draws less than 100watts would dehumidify anything less than a small locker. and since it seems to have no place to collect and dump water, i suspect it's just a low watt heater.


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## Idiens (Jan 9, 2007)

I just added a 72W de-humidifier to the rear cabin in addition to the 280W one in the main and fore cabin. Both extract water successfully. The big one starts off getting about 2 litres a week and drops to about 0.5 litres a week. The little one manages about 0.5 litre per week to start and is down to maybe 0.2 litres now. They are set to get the humidity down to about 70% inside when its 97% outside. I'm thinking that the marina electricity bill for the little one might be more than the cost of desiccant for the same volume.
I visit the boat at least once a week, so it's no problem to empty them.


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## LyleRussell (May 3, 2006)

Has anybody set their dehumidifier on top of a sink and let the sink drain seacock open? Obviously the boat must be out of the water to let a seacock open all winter. But it's a simple way to dump the humidifier.


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## Freesail99 (Feb 13, 2006)

LyleRussell said:


> Has anybody set their dehumidifier on top of a sink and let the sink drain seacock open? Obviously the boat must be out of the water to let a seacock open all winter. But it's a simple way to dump the humidifier.


If your boat is stored where it frezes, you could have problems, with the very least a broken hose. The hose that comes from the sink to the seacock. Also many times when the boats are in there jack stands they are not 100% level, which could lead to slow drainage and or breakage if it gets cold enough.


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## Faster (Sep 13, 2005)

jwms said:


> West by North (.com) has little AC/DC dehumidifiers that will collect several cups of water in a weeks time. I keep one in my 34' boat, moored in Tacoma, and have to empty it once or twice a week. I don't know what West by North sells them for but I was able to find one elsewhere online for under $50.


West-by-North has stopped selling those little dehumidifiers now that West and others are carrying similar products.

They do work fairly well, though.


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## HoffaLives (Feb 19, 2007)

Faster said:


> West-by-North has stopped selling those little dehumidifiers now that West and others are carrying similar products.
> 
> They do work fairly well, though.


i think they don't make them anymore. i stopped by west this am and the guy said they can't get them as the manuf. has discontinued the model.


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## Faster (Sep 13, 2005)

HoffaLives said:


> i think they don't make them anymore. i stopped by west this am and the guy said they can't get them as the manuf. has discontinued the model.


Hoffa - ask them to check stock in the Vancouver stores... also I saw some in Steveston Marine just a week ago.. Paynes in Victoria may have them too.
Steveston's price was around $120.....

If you like I can check Friday for you, my boats just a couple of blocks from there.


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## HoffaLives (Feb 19, 2007)

Faster said:


> Hoffa - ask them to check stock in the Vancouver stores... also I saw some in Steveston Marine just a week ago.. Paynes in Victoria may have them too.
> Steveston's price was around $120.....
> 
> If you like I can check Friday for you, my boats just a couple of blocks from there.


he said there's none in north america, at least showing on his computer. i appreciate the offer of hunting one down; let me make a few calls and see if there isn't one local.


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## SVCarolena (Oct 5, 2007)

*Heater*

I use an Xtreme bilge heater on my boat. I mounted it to a board with rubber feet so it won't move around, and keep it on the sole a couple of feed from the front engine cover, which I leave open. The heater turns on at around 40 F and cuts off at 50 F. I keep my boat in the water near DC and it is just enough heat to keep the diesel engine warm enough to start easily when I want to use the boat, keeps the cabin dry, and also keeps it warm enough to prevent freezing. Assuming all of Extreme's claims as to certifications are true, it is a very safe heater to keep runing unattended. However, I do try to check on the boat at least every week or two. It has been rather cold here this past week and I plan to go down to the marina on Saturday to inspect everything, I'll let you know if there are any problems. I also have a small ceramic space heater that I only use when I'm working on the boat (refinishing all the interior woodwork this winter). The Xtreme heaters are expensive, but I got a great deal on mine on Ebay (it was brand new).


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## HoffaLives (Feb 19, 2007)

nobody on the island carries marine dehumidifiers, but i noticed that home depot has one that's fairly small - 10"x16"X21". might go that route, although $250.00. and have no idea how loud it is.


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## TSOJOURNER (Dec 16, 1999)

Air-n-water (.com) have them online. This is where I got mine - the "ADS 300". (No affiliation, etc.)

It's not as quiet as I'd like but it really okay.


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## TSOJOURNER (Dec 16, 1999)

*dry, mold prevention on boat for the winter*

I work for Metric Restoration & associates. We do water damage and mold remediation work on houses and boats. Having lived in a Sailboat for a great portion of years of my life, I had to sleep in a mold infested sailboat for a while. I did use the golden rod and it is a great thing to have on board the whole time you is connected to shore power.
A dehumidifier does not work in temperatures lower than 60; in fact, the higher the temperature the better for a humidifier to work. So in the summer you can have a humidifier work by itself and in the winter you may need to add some heat. You must remember not to just add heat. Kim Hobson of KJS complete cleaning services says "Heat, moist and non ventilated areas are key factors for a perfect growth of mold environment."
Kim runs a mold remediation firm in Springfield, VA

Arturo Soriano Jr.

Metric Restoration & Associates


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## TSOJOURNER (Dec 16, 1999)

*dry, mold prevention on boat for the winter*

I work for Metric Restoration & associates. We do water damage and mold remediation work on houses and boats. Having lived in a Sailboat for a great portion of years of my life, I had to sleep in a mold infested sailboat for a while. I did use the golden rod and it is a great thing to have on board the whole time you is connected to shore power.
A dehumidifier does not work in temperatures lower than 60; in fact, the higher the temperature the better for a humidifier to work. So in the summer you can have a humidifier work by itself and in the winter you may need to add some heat. You must remember not to just add heat. Kim Hobson of KJS complete cleaning services says "Heat, moist and non ventilated areas are key factors for a perfect growth of mold environment."
Kim runs a mold remediation firm in Springfield, VA

Arturo Soriano Jr.

Metric Restoration & Associates


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