how much light?

[jamesdestin]

I need to replace some non-functioning interior cabin lights on my 25ft sailing cruiser. The trouble is that the existing ones are so corroded that I can't read the wattage on them. I don't really know how much wattage I need.

There are two separate cabins, the main and the V berth, separated by a sliding door. The main has 2 lamps and the V berth one rather small one. Use will be weekend cruising with probably no more than a couple of hours lighting each night (probably supplemented by some portable lighting). I'm guessing that the existing ones are probably about 10 amp. - probably need enough to read a book by.

I'm wondering about the 12v halogens like the Ikea ones mentioned in an earlier post, but are they suitable for main lighting? aren't they a bit too directional? The two in the main cabin would be mounted on the side of the cabin rather than on the ceiling so I think they'd act a bit like a torch shning in your face!

 

[fireball]

Our general lights are 2 x 10w bulbs ... the spots are 1 x 10w

This is just about enough to read by....

 

[roly_voya]

Spent a long time looking at this one!!
For the focsal a single celling mounted 10w light would give adiquate general light, 20w would be bright and might be better if you spend a lot of time reading in your bunk.
For the main cabin 20w would be fine execpt that if you mont any light on the side it MUST be a reading light type trowing light downwards otherwise you are right it will be horribly dazzeling. So you need one above each area, probably one over each settee plus chart table and galley. These give a cone of light spreading between about 60 & 90 deg. A ten watt light is bright enough to read by at about 4ft, 20w gives a range of abot 6ft so it depends on you headroom. I would expect 10's to be bright enough on a 26ft. The reading light will 'spill' enough light sideways to give general lighting.
If you fit quartz they give about 25% more light but the main difference is that it is a harder wight light rather than a softer yellow that you get from tungstan. This can be better for reading but less 'cosy'. The down side is that quatz bulbs are more prone to vibration and positively alergic to overvolatages so if you have any sort of 'clever' charger including 3 step shorepower sharger or alternator booster they fry the bulbs. I got about 6months out of bulbs living aboard. With your use this would be tollerable but carry spares!
If you want to go high tech take a look at DrLEDs They do a range of lights which give exellent output for almost no power, a 1.2w celling light gives about the same as a 20w tungstan, they are expensive though.
The final thought is that it is important to fit something you like the look of, there is nothing makes the cabin feel bleaker than a bare flurecent tube! and if you want real atmosphere nothing beats oil lamps (but you need a head tourch to read by!!

 

[EBoat126]

I got some IKEA LED kitchen lights in Cardiff, I think they're meant for under base units on the plinth. The lights are 12v DC so just chop the wire after the transformer & wire them straight up to whatever switch was on your previous. Admitedly it does look a bit like a 70s disco in there now.

 

[simonfraser]

the amount of light falls of with the square of the distance, twice the distance, you'll need four times the illumination

 

[jollyjacktar]

Years ago I replaced all my interior globes with 6watt ones that fitted the same socket. A bit dull but adequate and helps reduce risk of loss of night vision. Now carry several cheap LED torches and self contained "book reading" attachments where brighter lights are desired.

Helps to discipline the crew in ecomomic and conservative use of the luxuries in life and any other desirable virtues that go with this, 'like early to bed, early to rise, makes a man healthy, wealthy and wise".

 

[jamesdestin]

Thanks for the comments

things are a lot clearer now........