Association Forum - Crystal Dehumidifiers

Assn Members Area · Join

Home.

Association Forum

Ships Store

Cruising

Racing

Technical Tips

Photo Gallery - New

Boat Search - Updated

Manuals & Brochures

Swap Meet

Links

Officer Flag Line & Staff

Bylaws & Constitution

Members Area

Join the Association

Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.

Association Forum

Username:	Password:
Save Password
Forgot your Password?

All Forums

Catalina/Capri 25/250 Sailor's Forums

General Sailing Forum

Crystal Dehumidifiers

New Topic

Topic Locked

Printer Friendly

Author

Topic

watercayman
1st Mate

Member Avatar

Cayman Islands
49 Posts

Initially Posted - 03/31/2010 : 18:20:25

Hi Folks,

I've searched through the archives trying to nail down a solution for humidity. In Cayman, we don't have a lot of condensation issues, but just really humid air consistently. My goal is to keep the mold & mildew away.

Reading the posts here, I purchased a nicro solar vent... but am now a bit hesitant to put it on due to my fears about hurricane prep and having a potential 4" hole in the boat should the wind tear it off.

I also purchased a Dry-Z-Air unit, which I've been using regularly for several months -- it seems to draw a significant amount of water from the air. The problem is that I go through them in 10 days flat. While cheap, shipping them down here + duty starts to add up. Seems most forum members here get about 30 days out of them? Anyone want to comment?

Also recently looked at the Eva-Dry, since this would be a one-time purchase and then I can renew it. Seems like a great idea for me down here. Anyone use these? Can you comment on how you like them / how well the work / how long between charges?

I'd like to do it without having to run an electric dehumidifier if possible, so looking for other's opinions.

Thanks!

Mike

Mike Barrowman

Beneteau 311
P/O 1999 Catalina 250WK - #414
Cayman Islands

Edited by - on

OLarryR
Master Marine Consultant

Members Avatar

USA
3468 Posts

Response Posted - 03/31/2010 : 20:25:22

I have one of those EVA Dry units. They last a long time and believe they give okay performance recharged at home every couple of weeks or so. I also use a Nicro Solar Vent located in the main cabin and have the EVA Dry unit hanging from it's clothes hanger support above the Porta Potti between the main cabin and the VBerth area. I use my boat all year-round and in the last 4 years, only brought the cushions home one winter. My cabin area/cushions have no mildew or noticeable smell ...So these things seem to be working fine.

The EVA Dry, I purchased about 4 years or so ago from Boater's World. West Marine did not and still does not sell it. I also did not like the idea of continually changing out (fror new ones) those cardboard style dessicant holders. The PO had them onboard and i replaced them with the solar vent and the one EVA Dry unit. The EVA Dry Unit when dessicant is saturated with moisture, the dessicant color is visible thru the transparent plastic window and when the color changes, then you bring the unit home and plug it into a wall outlet. The body of the unit gets fairly hot. It takes overnight for the dessicant to dry out. i then double wrap it in plastic bags to keep the unit moisture free until I have it back onboard the next time at boat.

Edited by - OLarryR on 03/31/2010 20:30:07

watercayman
1st Mate

Members Avatar

Cayman Islands
49 Posts

Response Posted - 04/01/2010 : 07:20:37

Thanks Larry - this is very helpful. For me, half the battle is just getting stuff down here to the island, so the EVA Dry seems extremely well suited for my needs. I think I'll pick one up next time I'm in the States and give it a try!

Edited by - on

DaveR
Master Marine Consultant

Members Avatar

USA
2015 Posts

Response Posted - 04/01/2010 : 08:04:11

I think the solar vent is your answer and your wind worries are pretty much unfounded. We don't quite have your moisture here in Daytona Beach but pretty close. Last year I noticed the supply and exit hose to the head were starting to mold a bit so checked the battery in the vent; it was dead, so the vent worked in the light but not at night. replaced the battery and all is well. Good luck with it!

Edited by - on

Dave Bristle
Master Marine Consultant

Members Avatar

Djibouti
10005 Posts

Response Posted - 04/01/2010 : 08:12:05

It seems to me the dehumidifier and the solar vent would work at cross-purposes... I'd go with one or the other. The solar vent primarily removes the daytime, higher-humidity air from the cabin at night, drawing in cooler, somewhat drier air that has already dropped much of its moisture as dew. It works nicely for me in my climate--normally less humid than yours, and probably greater day/night temperature swings.

But if you're trying to dry the air chemically, the solar vent would draw out the dried air and draw in damp air. Instead, I would cover the companionway board louvers and otherwise seal the boat up as much as you reasonably can so the dehumidifier can do its job in there. (Of course the boat will always breathe somewhat, somehow.) Then when you're using the boat, you could seal up the dehumidifiers until it's time to close her up again.

I agree with Dave R. that wind isn't likely to affect a Nicro vent--it's pretty low, sleek, and sturdy, and is attached by the collar inside.

Edited by - Dave Bristle on 04/01/2010 08:21:40

Steve Milby
Past Commodore

Members Avatar

USA
5904 Posts

Response Posted - 04/01/2010 : 08:54:56

I've never had a solar vent on my boat, but have sailed on other folks' boats with them, and they seem to be very prone to people stepping on them when working the foredeck, or when raising and lowering the sails. The owner isn't likely to step on it, because he know's it's there, and is careful to avoid it, but the occasional guest who volunteers to put on the mainsail cover or to help in some other way is the one who is most likely to step on it. After you cut a hole in your deck and install one, you can't go back to the way it was, if you find that it didn't solve your problem. If it breaks, you have to buy another one to replace it.

Edited by - on

Dave Bristle
Master Marine Consultant

Members Avatar

Djibouti
10005 Posts

Response Posted - 04/01/2010 : 10:01:24

Steve's points are well-taken... raising two reasons for mounting it in the forward hatch: (1) people don't tend to step on the sloping hatch, and (2) if you decide to bag the whole idea, you can get a new hatch--Catalina Direct has them. I've seen many solar vents mounted in overhead hatches, probably for those reasons.

Edited by - Dave Bristle on 04/01/2010 10:01:56

OLarryR
Master Marine Consultant

Members Avatar

USA
3468 Posts

Response Posted - 04/01/2010 : 10:08:24

It is true that the solar vent and a dessicant removal canister are in conflict with each other. My thought is that the solar vent mostly does the job and the dessicant cannister is not needed. The issue is mainly that high huumidity daytime air that is present in the cabin will at nightime be cooled by the night-time temps and then the moisture condenses out of the air. The vent continually displaces the high humidity air (at a slow but effective rate) with cooler air that is less likely to have moisture condense in the cabin.

Having a dessicant canister in addition to the vent is not making things worse just that whatever moisture it pulls out of the air, that air may then be displaced out of the boat by the vent.

In my case, the PO had one or two throw-away dessicant cannisters which I replaced with the EVA Dry unit. After a month or two owning the boat, it occured to me that the vent cover he had in the main cabin....looked about the size that a Nicro Solar vent would fit into it if i popped off the vent cover. So, I purchased a 4" solar vent, popped off the cover and the vent fit perfectly.

It was my thought to use both devices because first of all, I already had both devices and.... the solar vent is in the main cabin and the air is exchanged at a very slow rate from air coming in the companionway door loovers (also in the main cabin) but the air in the VBerth area is more confined and with no air displaced except by the normal equalizing/exchange of warm and cool temp air, that area may be more susceptible for moist area to remain. Now I did not run ventilation/conduction/convection calcs on this but it seemed to me that the area forward of the main cabin is more or less a confined area and so that is why I thought it okay to also use the Eva Dry unit for that area..especially since I already had it. If some of the drier air up forward is also displaced by cooler outside air, it apparently has been a non-problem regarding my cushions which I mostly leave in all year-round. I have definitely been onboard some boats that their cushions smelled from mildew or something but since my cushions seem fine...I see no reason to alter my setup.

If I was starting off with no devices and had no vent hole in the cabin, then it's a question of cutting out a vent hole to install a solar vent or removing the moist air with a dessicant cannister. The solar vent once installed has very little maintenance involved - just removing the battery if putting a cover on your boat in the winter-time and replacing the battery perhaps 2-3 years later. But you have to cut a hole to install the vent wherever you choose to install it. The dessicant canisters, you have to continually replace or get an Eva Dry as you mentioned with a one time cost and it should last....well mine is going on over 4 years right now, then bringing it home every 2 weeks or so to recharge it.

Edited by - OLarryR on 04/01/2010 10:46:35

Dave Bristle
Master Marine Consultant

Members Avatar

Djibouti
10005 Posts

Response Posted - 04/01/2010 : 11:07:05

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by OLarryR
 ...the solar vent is in the main cabin and the air is exchanged at a very slow rate from air coming in the companionway door loovers (also in the main cabin) but the air in the VBerth area is more confined and with no air displaced except by the normal equalizing/exchange of warm and cool temp air, that area may be more susceptible for moist area to remain...<hr height="1" noshade id="quote"></blockquote id="quote">However, it turns out that humidity equalizes itself throughout an airspace very rapidly--much faster than temperatures equalize. If you dry the air in the salon, it will be virtually equally dry in the v-berth. That's why little passive dehumidifiers work at all. The position of either a vent or a dehumidifier is not very important, except that the solar vent might make a tiny bit of noise when you're sleeping.

The only reason I questioned using both is that the dehumidifier will be used up more quickly, but will be adding relatively little to the dryness.

Edited by - on

watercayman
1st Mate

Members Avatar

Cayman Islands
49 Posts

Response Posted - 04/01/2010 : 19:40:29

I really love this place. Thank you all for your time and your thoughts. Some great insight.

Dave B - My plan was originally exactly what you said - put the vent in the forward hatch, and then if I changed my mind or a major hurricane came, replace the hatch. (DaveR - The hurricane thing terrifies me with the boat, as we got run over by Ivan when it was 160mph for 18 hours - I tend to think of worst case scenarios now, and agree that they are sometimes unfounded :)

I think I'm going to take it one step at a time. I've got the Dry-Z-Air now, and it really seems to work well. But, it's going to get tedious and expensive to keep shipping in and re-filling the thing... so - I think I'll try the Eva-Dry next and see how that pans out. If it's good - I'll stick with it. Else - maybe time for a new hole-saw.

When i bought the boat, it was in good condition, but a thin layer of mildew sat on many surfaces, and once it gets started down here, it's tough to stop. After 3-4 weeks of scrubbing and cleaning cushions, I'm hoping to keep it at bay permanently.

Edited by - on

OLarryR
Master Marine Consultant

Members Avatar

USA
3468 Posts

Response Posted - 04/01/2010 : 20:25:16

Dave...what you say makes sense. Those little dessicant canisters are passive and are advertised to work for the whole inside area. So, it should be sufficient by itself. believe the Nicro also does as good or better job by moving the high humnidity air out before it condenses at night. Another factor -My old Nicro Vent (as discussed in a previous posting thread) had developed a noise and I have not been fully successful eliminating that noise, though, i still have some ideas on how to rid it of the noise. But then......

When I was up at EB and staying in Mystic in your neck of the woods the other week, I visited that West Marine that's fairly close to your house and noticed they had the Nicro Vents on sale (still expensive but less than what they normally charge: 4" for $119 vs $159). When I returned home, I visited the West Marine in my area and they were also on sale, so I decided to buy a replacement for my Nicro. The fact that the new Nicro has a convenient on-off switch was what pushed me into the buying mood. I'll be bringing it down to the boat this weekend.

But do like the Eva-Dry with the color changing dessicant crystals that recharge in the AC outlet at home. I guess I am at least for now in the habit of using both, though, if used properly either will probably do the job.

Edited by - on

Dave5041
Former Mainsheet Editor

Members Avatar

USA
3758 Posts

Response Posted - 04/01/2010 : 21:42:06

You can buy buy silica gel in bulk, put it in your own canister and dry it in the oven at home when it is saturated. It has to be heated to about 220º to release its moisture, and you could probably get that temperature in a rudimentary solar oven in your cockpit. One source:: http://www.silicagelpackets.com/

Edited by - on

OLarryR
Master Marine Consultant

Members Avatar

USA
3468 Posts

Response Posted - 04/02/2010 : 03:22:21

Dave - Good point ! You could be self sufficient and take care of the dessicant yourself but....like so many things onthe boat, it's nice to have things that do not need to be attended. Since the dessicant lasts only about 2 weeks or so, it means another chore to be manually drying the stuff using the oven, etc. I don't even like to cook...usually stay away from the stove. My wife does almost all (she would say "all") cooking. I take care of the dishes.

This kind of reminds of an unrelated topic I brought up awhile ago - What to do with the fenders on the boat. I use to wedge then between the stays and the cabin sides when i went sailing and asked advice as to what other sdid to manage their fender tending. I got great responses ! What I did was to hook up a cable with turnbuckles between the cleats on my finger slip and I attached 3 fenders at the midpoint. The cable stays tight and the fenders remain alongside the finger slip at same height all the time. This way, it is another one less thing to tend to when going sailing. I never mess with fenders coming in or out of the finger slip. I only mess with my addl fenders stored in the dumpster when i visit another docking area.

I bring this up because part of the thing with keeping the cabin mildew free is to not add additional chores. Plugging in the Eva-Dry into the AC outlet is not so bad but the Nicro Solar vent is even better since it requires no attending to at all except to remove the battery if putting a cover on in winter time or to replace the battery after a few years of service.

But...I admire your thoughts of how to be more independent with these choices. There are certainly things we can all do...saves dough and within our capability given some thought.

Edited by - OLarryR on 04/02/2010 03:27:10

Topic

New Topic

Topic Locked

Printer Friendly

Jump To:

Association Forum

Notice: The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.