CHEAP solar ventilators

[DianaOfBurlington]

I have a need for several smallish solar-powered exhaust ventilators, preferably with reversing switches to make them work as intake fans. I need about 4. One is for the cabin, leading through 3" hose through a Dorade box in the cockpit to the q-berth. One is for the perpetual evacuation of gasoline-tank fumes (beats having a 12vdc blower and switch to forget to turn on). Two are for the anchor-rode lockers which otherwise hold slimy wet stinky rope until it rots and gets replaced.

There is one in the foredeck hatch for the general ventilation of the head and cabin. These are all for smaller or more specific areas.

The ventilators need to be stainless and not so fragile that you can't slide a foot into them on the foredeck. (The plastic ones like Beckson's break from this.) They need to be small-- 3" would be ideal; anything over a 4" hole in the deck is getting too big. The OD of the thing needs to be closer to 6" than to 9". They need to be cheap-- or I am looking at over $400 worth of deck fans here.

And, yes, I have been considering just a regular 12vdc exhaust fan and uprating the solar panels; but I'd rather not rely on the house system. Three or four days of rain and clouds at anchor and the thing would still be running (and unnecessarily in that cool weather too) --as well as all night. No.

I have been all over the Web like most people would naturally do and have found nothing lately. I am hoping someone has found something beyond the usual channels.

Here is what I have found--
-- Marinco/Nicro have a 3" size; but it is expensive and eats rechargeable batteries, to the tune of 3 or 4 a year. That's not enough to get through one winter on one battery.
-- The nice ICP one in the WM catalogue appears nowhere else so I can get detailed specs on it. If anyone has one of these fans, do let me know.
-- As soon as you say 'marine' the price goes up. The Airstream site was a big help; but they don't seem to know much about boats (one guy thought it wouldn't hold up at 65 MPH. Sorry to tell you, but that's just a typical hurricane to us).
-- I like the Sundance and Sunforce ones; but they're too expensive.
-- I could retain the 3" cowl vents in the Dorade box but having the solar vents in the rode lockers is a must.

If you've got a good idea, please post here for the elucidation of the masses; or just email me and I'll try to exchange the favor with whatever you need as well.

 

[Ed Schenck]

Can we assume that you do not want to run wire? Thus no 12v or 110v options? I mention 110v because there are some computer fans that run on milliamps. I have one rated at 160ma but they come smaller. And hooked to a timer for a few hours a day would take very little from a battery bank. What is that, about 1.6 amps from 12v? Assuming(that word again) that you have an inverter of course.

 

[Tim R.]

I would not use a "cheap" solar ventilator and run gasoline fumes through it. In fact, I would not even use a Nicro to do this.

Mild ventilation is fine but you really should use a proper blower to exhaust gasoline fumes. The solar powered vents are not strong enough to overcome strong wind gusts.

I have a Nicro in my forward head and it has run continuously for over a year on the same battery.

Just remember, some tings are marinized for your own good. Also remember that you get what you pay for.

 

[Ross]

Computer fans are 12 volt and not reversable. Gasoline vapors are heavy and you want to be absolutely certain that you are venting them. I would not trust a computer fan for that. I have been ventilating my boat for 12 years with computer fans and a dedicated 5 watt solar panel they run when the sun shines. I always dry my anchor rode on dech before I stow it.

 

[Mike B1026]

Another vote for computer fans. They move a lot more air than those Nicro's. (They are rated in CFM's)

 

[thinwater]

I always dry my anchor rode on dech before I stow it.

I hear that a lot, but I've never understood it.
* Raise anchor,
* get underway with anchor stowed, it may even be raining,
* ... and if there is a windlass it's right into the locker anyway.
* Lower anchor at next stop.
* Drying a salty anchor rode would take a good 24 hours.
* How do I keep the fore deck dry underway?

I can't think when I would dry it. I guess if I only motored in calms.

____________________


Computer fans are a good deal. I never really understood the need for the batteries; the night air is full of dew, so wait until morning.

 

[Ross]

I ship my anchor by hand and back and lay the rode out along the rail. It drains most of the water in the first hour. Damp is one thing for the anchor locker dripping wet is quite another. You do have drains in the anchor locker. Yes?

 

[Stu Jackson]

Computer fans may not necessarily be IGNITION protected, like blowers are. For use with gasoline fumes, you'd need, want and require that feature.

 

[tommays]

I was not aware the H25 ever had and inboard gasoline motor ?

 

[DianaOfBurlington]

JC's apology

Wow-- I am away for a few days and all this happens!

1. I have a 110vac computer fan. I would NOT use it for exhausting gasoline vapor. It does not run on mere milliamps, perhaps from being very old (1980s) but the thing about these things is that they DO run forever-- they are made to. I am using it to exhaust the outflow from the microwave-- which is located in the forepeak (for reasons perhaps only other H25 owners can fathom). The microwave is getting built-in and so airflow would be a problem with the typical house-grade unit.

I would not consider anything 110vac anyway since this is of little use at anchor in a 25-ft boat with no inverters or generators.

2. I know of ONE H25 with an inboard. I really should have restored this boat with the idea of installing one (to make mine the second one) but didn't think of it till all the under-cockpit cabinetry was reconfigured to how it is now. I do, however, have an under-cockpit gasoline tank. The original plan for the H25 fuel can was awful by today's standards; and now I have twice that capacity for 48 hours' running time. The solar-powered ventilator should be enough to exhaust fumes from an otherwise sealed compartment (the under-cockpit area is sealed enough to not 'breathe' from or into the cabin) especially in the absence of any ignition source in the same end of the boat (the exception being the propane cooker and lamp in the saloon).

The real reason for fumes blowers is not to keep air moving but to quickly exhaust what may have settled in the bilges whilst the boat was sitting. ANY movement of air through the boat is enough to dispel the bulk of it-- this is why it is recommended to run the blower 4-5 minutes before ignition-- because it's all been sitting, probably all closed up. Constant movement, no matter how slow, whilst the boat sits over about 24 hours, is WAY better than attempting to move 20 hours of settled vapor in 5 minutes. Even opening a hatch is enough to get much of (even settled) vapor stirred-up. My system has a hose dropped into the lowest part of this compartment so that in the first 15 seconds it is sucking from that region.

3. The stock anchor-rode locker is inadequate for two separate rodes. It is up in the forepeak where the weight of a damp anchor line is not desirable. My foredeck is too small with the primary's anchor roller to accommodate a cowl vent. And, yes, it drains into the bilge, about the worst place to accumulate river- and bay-bottom slime. I am running a drain tube from that compartment directly aft to the central part of the bilge, bypassing the under-v-berth lockers so as to keep them dry.

My idea is to move the rode back to the sides of the v-berth. I don't use the v-berth and by now it has the tool box, hanging locker, and the aforementioned microwave taking up about 40% of its width; so it's a single bunk about 32" wide. I intend to drop the P & S rodes into vinyl trash cans mounted about 24" forward of the bulkhead (farthest aft they can go because of other stuff). Aside from moving weight aft, this enables me to stand in the foredeck hatch and winch in the line and perhaps later to reach over and feed it into the deck pipe to the trash can (which is fitted with a through-hull draining into the bilge)

This is a singlehanders' trick I have long wanted to do (the last time I tried it, I was winching the anchor up by a jib winch). The last thing we solo sailors need to do is to scurry all over the deck at a crisis moment like weighing anchor; and if it can't be done under sail alone it can become a terrific nightmare.

4. Of course I won't use junk nor non-marinized stuff; if I were happy with that I would not have posted on a boat-owners site but gone to the RV, Airstream and camping places and bought something in plastic or of ferrous metal (i.e., junk). There is a BIG difference between the $189 Nicro ventilators (which ARE adequate for pumping out fumes, if they only lasted long enough) and a $39.95 piece of junk from the RV place. I do want stainless both for durability and looks. I do want them to be solar, to avoid depleting the house battery bank. And I need for them to be 3" hose size, not 4" as most are; because I have a 25-ft boat with 4-6"-wide side decks. I just thought maybe someone has found something off the beaten (West Marine) track, maybe 7" wide (I don't care how high or how deep) for between those two costs.

It's a shame because a million years ago in about 1980 I knew of a small (maybe 4"-diameter) solar panel that could be fitted into the forward end of one of our nice varnished-teak Cherubini 44 Dorade boxes and could be wired to power a blower (like a computer fan) installed in the air duct there. It was like the panel alone of the Nicro-type solar vent. Alas, this has completely vanished from the market-- I have looked and found nothing. I guess I'm lamenting its loss.

I do thank you guys for the suggestions and the effort to help. I suppose I will have to budge much more for this than I wanted to. Already the Dorade box aft is configured for cowl vents and I may just use those and the Yellowtail blower. The anchor rode vents are a must however; and I am inclined towards that ICP one.

When I get some photos of this arrangement I will post them on the blog.

 

[Maine Sail]

The real reason for fumes blowers is not to keep air moving but to quickly exhaust what may have settled in the bilges whilst the boat was sitting. ANY movement of air through the boat is enough to dispel the bulk of it-- this is why it is recommended to run the blower 4-5 minutes before ignition-- because it's all been sitting, probably all closed up. Constant movement, no matter how slow, whilst the boat sits over about 24 hours, is WAY better than attempting to move 20 hours of settled vapor in 5 minutes. Even opening a hatch is enough to get much of (even settled) vapor stirred-up. My system has a hose dropped into the lowest part of this compartment so that in the first 15 seconds it is sucking from that region.

The concern folks have expressed is that bilge blowers are "ignition protected" meaning the fumes can't be ignited by the blower. Solar vents do not carry an ignition protection rating and could have open spark or the ability to ignite fumes. The ABYC standard that applies to this is H-2 which you probably have at work.

The importance of ignition protection is stressed in H-2:

"2.6.3.1.4 Blowers shall meet the external ignition protection requirements of UL 1128, Marine Blowers, UL 1500, Ignition Protection Test For Marine Products, or SAE J1171, External Ignition Protection Of Marine Electrical Devices."

H-2 also covers sizing the blowers, natural ventilation etc. etc..

 

[DianaOfBurlington]

Thanks, Maine, for the update. I'm not sure I was thinking of sparks. The basic difference in sparkproof and nonsparkproof motors is brush vs magnet motors-- so I am told; and it makes sense. I have here a bilge blower by Attwood that doesn't have a brushless motor. Could anything be more shortsighted than that (even including me)?

I believe I will resign myself to having the Yellowtail blower for the fumes and the solar ones forward. I just still have not found inexpensive ones with SS guards or shells on them; and we know what will happen if they're plastic (which most under $120 are) and stepped on. This also gets me out of the woods as far as modifying the existing Dorade box to accommodate the wider diameter of the solar fans.

I just thought it was a cool idea.

 

[JohnS]

My idea is to move the rode back to the sides of the v-berth. I don't use the v-berth and by now it has the tool box, hanging locker, and the aforementioned microwave taking up about 40% of its width; so it's a single bunk about 32" wide. I intend to drop the P & S rodes into vinyl trash cans mounted about 24" forward of the bulkhead (farthest aft they can go because of other stuff). Aside from moving weight aft, this enables me to stand in the foredeck hatch and winch in the line and perhaps later to reach over and feed it into the deck pipe to the trash can (which is fitted with a through-hull draining into the bilge)

Any chance the bottoms of those trash cans will be above waterline? If so, you could have them drain overboard instead of the bilge. A check valve in the drain line would help to prevent water coming back in when heeled.

 

[dscsr23455]

I am currently waiting for my Sunforce solar vent from Lowes on line. It is the same I found from Defender etc. just cheaper. Hope that helps.

 

[DianaOfBurlington]

John, that's a good point and I did think of that; but I was sort of loathe to consider that a plastic trash can from Office Max is going to keep out seawater. What if it froze or cracked? They are above the bunktop and therefore close to if not a little over the DWL. But draining them into the bilge is not a problem. Under the aft end of the v-berth is the holding-tank compartment where all the cabin through-hulls (except the galley sink drain) are. I can lead the rode-bucket drains past here to the head/shower bilge where they can be kept plugged till I feel like draining them and flushing them out. The existing (way-forward) rode locker already drains here-- not overboard out the bow like some people have it.

I don't like draining anything overboard that's too close to the waterline because of the potential for taking ON water in the event of snow, unintentional improper loading or the case of already taking on water somewhere else that causes the boat to ride too low. Anything within 4-6" of the loaded waterline should have a shut-off valve; in the boot stripe or below and it should be a proper seacock. I don't know that having the rode bins in this location would make those outlets either aesthetically pleasing or easy to get to; and they'd be two more things to worry about.

(I am of course putting check valves on the cockpit drains since my new ones are going out through the cockpit sole rather than in the back bulkhead-- a cost-savings idea of Hunter's, and worthless. These are probably low enough to merit seacocks or ball valves as well; but in the event of leaving them closed one could end up with a different kind of catastrophe. The through-hulls-- above waterline-- are all stainless steel on this boat (looks better than plastic). Should the drain hoses break and admit water, this is what God invented tapered wooden plugs for

 

[DianaOfBurlington]

dscsr23455, I'll be eager to hear how that little solar vent works out for you. Do let me/us know.

BTW-- Hurley 20, nice little boat. How do you like it?