Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 11-05-2006, 17:28   #16
Registered User

Join Date: Sep 2005
Location: Puget Sound
Boat: 1981 C&C 34
Posts: 49
The solar vents work okay. There's one in the head and it runs quite a bit considering its cloudy ALL the time up here. They don't move a lot of air but some is better than nothing.

The battery only lasts a year or so before it won't hold a charge. Replacements are a lot cheaper at Radio Shack than they are from Nicro.
__________________

__________________
JohnWms is offline   Reply With Quote
Old 12-05-2006, 03:39   #17
cruiser

Join Date: Aug 2005
Location: No longer post here
Boat: Catalac Catamaran
Posts: 2,462
I've been contemplating this problem for a while now. In my Cat we have a forward stateroom on the bridgedeck which has no ventilation. In Florida, summers get slightly uncomfortable (OK, that's a bit of an understatement).

I was wondering about trying 12" electric automobile radiator fans. They draw 8-12 amps at 12 volts (way too much current) but move 2000 - 3000 cfm. So, by reducing the DC voltage to some lower point, say 4 or 5 volts will in fact reduce their current draw and motor speed, right? Should move lots of air and be silent as well without killing the battery.

Any thoughts?

Rick in Florida
__________________

__________________
Tropic Cat is offline   Reply With Quote
Old 12-05-2006, 05:43   #18
Registered User

Join Date: Sep 2005
Location: Puget Sound
Boat: 1981 C&C 34
Posts: 49
When you say *no* ventilation does that mean no dorades or anything? It seems like you'll need some way to have an "in" and and "out" so any fan can work better.

Otherwise, your assumption is correct in that reducing the voltage reduces current draw, to a point. It *is* possible to damage some electric motors with too little voltage. They can draw too much current to compensate for a voltage drop.

Maybe first pick up one of those Caframo fans and experiment with placement? I tend to like to build things in permanently too but the portable fans have been a pretty good solution for me.
__________________
JohnWms is offline   Reply With Quote
Old 12-05-2006, 06:30   #19
Registered User
 
Doghouse's Avatar

Join Date: May 2006
Location: Hampton Roads, va
Boat: Catalina 387 - Magical Dreamer
Posts: 176
Images: 1
I like the idea of the cardboard door with fans to test. I may try that this weekend. I have 12 older 210mm fans from a server we tossed out at work, and I may see how they do. (just 3 or 4) I figure 4 would be about 2ah draw so my battery should be able to handle that for 12 hrs. I will have to do some testing. Thanks for all the tips. NewEgg.com has 105 cfm fans for 13.99 with a speed control so that may be a cheep starting point for anyone who wants to experiment. I will post the results of my tests here as soon as I have some.
__________________
Doghouse is offline   Reply With Quote
Old 12-05-2006, 06:48   #20
cruiser

Join Date: Aug 2005
Location: No longer post here
Boat: Catalac Catamaran
Posts: 2,462
"no ventilation" means it's damn hot in there!! I have openings in the bulkhead which open into the salon, and a hatch. Plenty of room to pull and push air around, I just have to come up with a power efficient way to do this.

I advocate large fan blades turning slowly. They move a lot more air than those tiny (and noisy) muffin fans.

Rick in Florida
__________________
Tropic Cat is offline   Reply With Quote
Old 14-05-2006, 00:40   #21
Senior Cruiser
 
Alan Wheeler's Avatar

Cruisers Forum Supporter

Join Date: Dec 2003
Location: Marlborough Sounds. New Zealand
Boat: Hartley Tahitian 45ft. Leisure Lady
Posts: 8,038
Images: 102
Rick, just as a thought, what color is the hull?? Dark colors will heat the insides up like an oven. You could solve some heat related problems by changing the hull color to white, if it is say Blue or Red or what ever. Just a thought.
__________________
Wheels

For God so loved the world..........He didn't send a committee.
Alan Wheeler is offline   Reply With Quote
Old 14-05-2006, 07:35   #22
cruiser

Join Date: Aug 2005
Location: No longer post here
Boat: Catalac Catamaran
Posts: 2,462
Alan, I appreciate the thought, but the Bridge deck is white, the Hulls are cream colored. The real problem is 95 degree days and clear blue sky, ie... direct, radiant sunlight.

Here are the openings I plan on using for fan(s). I think these circular cutouts were designed for passive ventilation but look perfect for large slow turning fans.

Rick in Florida

__________________
Tropic Cat is offline   Reply With Quote
Old 14-05-2006, 07:36   #23
cruiser

Join Date: Aug 2005
Location: No longer post here
Boat: Catalac Catamaran
Posts: 2,462
oops, I apologize for the large photos
__________________
Tropic Cat is offline   Reply With Quote
Old 14-05-2006, 11:18   #24
Senior Cruiser
 
Talbot's Avatar

Cruisers Forum Supporter

Join Date: Jun 2004
Location: Brighton, UK
Boat: Privilege 37
Posts: 3,579
Images: 32
rick, dont you have a hatch above that compartment (there is on either side on the 9m) If so, a wind scoop will solve your problem (see http://www.seamarknunn.com/catalog/items/item4032.htm)
__________________
"Be wary of strong drink. It can make you shoot at tax collectors - and miss."
Robert A Heinlein
Talbot is offline   Reply With Quote
Old 14-05-2006, 12:22   #25
cruiser

Join Date: Aug 2005
Location: No longer post here
Boat: Catalac Catamaran
Posts: 2,462
Mark, Yes, I do have a hatch in the stateroom, to the side of the berth over the companionway.

I checked your link, it sort of looks a bit ostentatious, and I can't figure out what supports it on the cabintop. Does it actually work?

Rick in Florida
__________________
Tropic Cat is offline   Reply With Quote
Old 14-05-2006, 13:44   #26
Senior Cruiser
 
Alan Wheeler's Avatar

Cruisers Forum Supporter

Join Date: Dec 2003
Location: Marlborough Sounds. New Zealand
Boat: Hartley Tahitian 45ft. Leisure Lady
Posts: 8,038
Images: 102
Thanks for the Photo. No it's not to big, it's great. Interesting layout, I take it you can walk around the front of your seating area?
OK, the important aspect of ventilation is "air flow". You need to draw air through. If you place a fan at the doorway, you will cycle 98%of the air around that fan only. That equates to wasted power. You need to make the fan the exit and the inlet at the opposite end. Whether that means the fan at the door or not, is up to you. But drawing air through the entire cabin is essential. My suggestion is that the cabin entrance is the "Intake" and the fan goes the opposite end.
Can I see a window open on the left up forward? or is that a bug screen only? A fan there would be good. Otherwise, you need to place a Dorade vent on the cabin top forward somewhere. You can place a fan inside that for very calm days, but it breezes, the Dorade cowl facing forward will allow air flow. You can swivel the cowlings around to suit wind direction and as wind is usualy on the nose while at anchor, it allows a natural air flow through the cabin and out the hatch.
If you place a fan inside, DC fans can be reverse rotated. So a simple switch could mean you could force air in either direction to suit conditions and direction.
Hope that helps.
__________________
Wheels

For God so loved the world..........He didn't send a committee.
Alan Wheeler is offline   Reply With Quote
Old 14-05-2006, 14:16   #27
Senior Cruiser
 
Talbot's Avatar

Cruisers Forum Supporter

Join Date: Jun 2004
Location: Brighton, UK
Boat: Privilege 37
Posts: 3,579
Images: 32
rick, these wind scoops work well. They are held up by rope from the top secured to something convenient like the shrouds, spinnaker halyard etc.
__________________
"Be wary of strong drink. It can make you shoot at tax collectors - and miss."
Robert A Heinlein
Talbot is offline   Reply With Quote
Old 15-05-2006, 10:24   #28
cruiser

Join Date: Aug 2005
Location: No longer post here
Boat: Catalac Catamaran
Posts: 2,462
Alan,

I have 6 side windows which can be removed and the openings hold screens. Unfortunately, only one of these is in that forward stateroom (which is on the other side of that bulkhead in the photos). In addtion, that stateroom has a hatch. The window in the photo is in the head, portside forward.

Well, I'm boatless for a week or so. I just dropped the boat off at the yard to have the starboard shaft looked at. Alan, the weather here is warming up, and I fear I have moisture in both fuel tanks again. When motoring this morning, white/gray steam from boat engines for the entire hour of motoring.

Rick in Florida
__________________
Tropic Cat is offline   Reply With Quote
Old 15-05-2006, 13:33   #29
Senior Cruiser
 
Alan Wheeler's Avatar

Cruisers Forum Supporter

Join Date: Dec 2003
Location: Marlborough Sounds. New Zealand
Boat: Hartley Tahitian 45ft. Leisure Lady
Posts: 8,038
Images: 102
No way water in fuel will do that. If you have water cooled exhausts, that is all it is. quite normal. If it is dry exhaust, it maybe a bad sign, such as a blown head gasket. Water in fuel bad enough to cause steam in the exhaust will stop an engine dead. It takes very little to stop the engine. Even one drop can do it. If you are lucky, smaller than a drop will pass into one cylinder and may not be noticed, but it certainly won't be seen as steam out the exhaust.

If it is a Gasoline engine, then that is different again. For every 10ltrs of fuel burn't, produced is 1 ltr of water and 1/10th ltr of sulphuric acid.
__________________

__________________
Wheels

For God so loved the world..........He didn't send a committee.
Alan Wheeler is offline   Reply With Quote
Reply

Tags
battery

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Yanmar Tips GordMay Engines and Propulsion Systems 18 29-07-2012 06:04
High style, low rates: Spanish paradores CaptainK Europe & Mediterranean 0 15-04-2006 02:12
RF Noise from Mastervolt Alpha Pro BachAndByte Electrical: Batteries, Generators & Solar 4 21-08-2004 05:33



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 12:16.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.