Friday, 28 November 2014

Boat Improvements. (1)

As always things in life undergo gradual change. This started me thinking about what changes I could make to the boat to improve life aboard.  Because our requirements have changed with retirement. From long weekends and occasional holidays. To spending a great deal of time on the boat but not quite as live-a-boards. 

My old boss had a rather interesting question that he put to the staff meetings. It would go something like this - "I know that we may not all be happy working here. But if there was one thing that you could change to make things better what would it be." Over the years some changes were made to working practice as a result of ideas being expressed.

I would never make a change just for the sake of it. There would always need to be a tangible benefit from making any change. Since we purchased the boat, we have made a few small but significant changes. In this instance because of the readily availability of a new technology.

The first change was to modify the on board lighting systems. Spread around the boat are a mixture of ceiling and wall lighting. The changes did not involve purchasing and then installing new fittings. It involved a simple exchange of 'bulbs'. We changed from using halogen bulbs to the new LED (light emitting diode) types. 

If a light bulb was to fail, its a simple task to change it and so it is with LED light bulbs. Its the same 12 volt 'electrical power' that is being used. It does not require the services of an electrician. It might not as in our case require the use of any tools. However, as a result of new technology selecting LED lights does require a bit of forethought if you are to get it right first time.

LED Type
In our case the bulbs used in the ceiling fittings are designated as being G4 types. These are used in many different applications. However, the fittings for our halogen type had a reflector. 

Fitting the new LED type of bulb means that the reflector is no longer required and can be ignored. because The bulb shape has changed and the led type now lays flat across the fitting.

The new led lights come in different colours, by this I don't mean red white of blue. But a small variation in couler usually expressed by temperature. In this case I don't mean temperature as hot or cold to the touch. 

Spot Light
We talk about a cold white (slightly blueish) or a warm white (slightly reddish) light. This colour is measured in degrees on the Kelvin scale.  Depending on where the lights are to be located so you can create an ambiance.  We used - 5500k - in the kitchen area and - 1800k - lights in the bedroom and lounge areas.  A more pure white light - 3500k - was used in spot lights used for reading.

Ceiling Fitting
So why did we choose to change the internal lighting on the boat. There are a number of reasons why we made the choice. One was to improve the ambiance as we always felt that the halogen light was too bright in the lounge area. Because the lights were bank switched in the lounge (all on or off) we even removed every other bulb just to lower the intensity of the light.

Halogen lights get very very hot almost within seconds of being turned on. When it comes to lighting any heat created is wasted power.  Halogen lights are electrically very inefficient. The LED lights get ever so slightly warm to the touch after they have been switched on for a while. LED lights are electrically very efficient. However, the main reason for the change was to lower the demand on the leisure battery bank when providing electrical power for  lighting.  

When we purchased Rosie the lighting configuration was as highlighted in the area list below. The figures in brackets are the power consumed for each bulb in the unit of power consumption which is expressed as watts.  The conversion of Watts to Amps at fixed voltage is governed by the equation Amps = Watts/Volts Saloon: 6 (20w) and 4 (20w) Kitchen: 4 (20w) Bathroom: 4 (20w) Bedroom: 6 (20w) Aft cabin: 2 (15w) Navigation: 3 (15w) Tunnel: 1 (40w)

Saloon:  10 x 20 = 200 watts. Kitchen: 4 x 20 = 80 watts. Bathroom: 4 x 20 = 80 watts. Bedroom: 6 x 20 = 120 watts. Aft Cabin: 2 x 15 = 30 watts. Navigation: 3  x 15 = 45 watts. Tunnel: 1  x 40 =  40 watts. Giving a grand total of 595 Watts.  which converts to 595/12 = 49.58 Amperes. 

However, when I measured the actual amps used with all the items turned on. Power consumption measured 56.2 Amperes on Rosie's digital ammeter. The actual power used will vary a little for each bulb. The figures quoted on the packaging are nominal. All the little additional bits in our case totalled about 6 amps or 72 watts just over 2 extra watts per bulb.

If all the lights were to be left switched on, 0ur 500ah leisure battery bank would be depleted very quickly. In 5 hours our battery bank would have given up 281 amperes which is more than half of its theoretical capacity. (500ah) I use the word theoretically as the quicker you discharge any battery the less total capacity the battery has to deliver. In 5 hours at this rate our leisure batteries would have been well on their way to being discharged.

With the majority of the lights converted over to led. When all the lights are turned on throughout the boat our power consumption is 3.9 amps or 37 watts. Which is equivalent to just 2 of the old halogen bulbs.  Which is a significant saving over the original 56.2 Amperes (674 watts) of halogen consumption. We could leave the lights turned on for 72 hours to half discharge the battery bank now. Which is 14 times longer than before.


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