cooling

mike and Judy · Guru

cooling

Rolly · Guru

Any extra insulation will help provided the airfow around the motor/heat exchanger is not obstructed.
One of the Aussie made brands comes with 100mm of insulation as standard and is much more efficient.
Waeco etc. make theirs with thinner insulation in order to keep the size to more managable proportions.

Re. the wind generators, the sea-going sail boat people love them.
They rarely put out more than a couple of amps but keep charging after the sun's gone bye-byes.
There are quieter models available - at a price.
Most yachties have PV panels as well.

-- Edited by Rolly on Sunday 29th of March 2009 10:34:05 AM

dave06 · Guru

yep any extra insulation that you could whack on a fridge has got to be beneficial, however you must be carefull not to block up any "ventilation" holes front and back but apart from that it is a good thing, I would estimate about 5%- 10% points of thermal exclusion for every 10 mm of foam, also a thermal fan strategically positioned to remove the vented hot gases would be an enormous benefit

it gets to the stage ( and this is well proven) that enough foam or any good insulation could aleviate the need for any further cooling input, in other words it will keep the temperature inside a "constant" for an extended length of time which is a good thing for us campers

take the case of a good quality esky, put ice in there and with no additional cooling required I have seen ice emerge after ten days (the big green fibreglass ones come to mind, dont know who makes them)

the idea is edzacary the same

ah wind turbines, a big one will generate a large ammount of power very efficiently and quietly but little ones dont generate a great deal but do it very efficiently and quietly

I am a big fan (pardon the pun) of wind turbines and I have been lobbying the council to let me erect one in my backyard (approx 90 feet high and a blade span of 60 feet) I had intentions of cornering the market, well our block anyway, world domination would come later, but council will not approve such a thing

now what was I saying OH YEAH!! wind turbines, big ones good, little ones good too but not much power output but where they win is that they do it 24 hours a day and seven days a week, for no cost now as anybody knows if you have a pinhole in a 5,000 gallon water tank eventually that tank will run dry

same principle with the little turbine it is meant as a "trickle" or "maintenence" charge, small ammout all the time, if you leave a battery discharged or partially discharged (particularly lead acid) then the thing will "calcify" and bugger up very quickly it is much more desirable to have a battery "fully charged" than slightly charged

now fully charged is not as it seems, the maximum you will achieve with a vehicle alternator driving down the road is about 65%-70% charge these figures are argued by experts but commonly accepted as being between these figures, BUT with a "trickle charger" such as a small solar panelor a turbine over an extended period you can actually achieve a figure way above the above rated percentage points, which is highly desirable by campers, I will not quote figures here because even the experts differ highly here with their figures

this opens up another prospect if there are people out there contemplating doing this (please bear with me, simple question complex answer) if you charge a lead acid battery or batterys beyond the 70% stage then you will produce enormous ammounts of hydrogen and oxygen, far too much for a sealed box, you must ventilate these gases or an explosion at these concentrations will be imminent, below 70% and the gases are far less significant and not AS dangerous

because hydrogen and oxygen are both lighter than air they will gravitate to the top so please put large air vents straight above the batterys and also place one in the bottom of the container as well, in case of a bit of wind pushing the mixture down

a sealed battery will also produce these gases and they have a pressure valve built in which releases excess gases so vents are still needed when charging over the 70% magic barrier, agm and gel Batts produce the gas as well but it is usually taken up by the opposing plates and therefore are not a danger these can be sealed in a container without fear

I hope I havent bored you too much but as I said simple question complex answer. I will list this in the techies forum as well for ageneral reference

Cruising Granny · Guru

How green is the Pirie Council?
If they deny you the practical private wind generator, what would they say to a wind farm?
My daughter lives at Edithburgh in view of the wind farm. A graceful ballet of blades.
I think they are a silent statement to sustainability, and the farmer on whose land the turbines are constructed get paid for the rite and can still farm the land.
Not very progressive at Pirie?
Cheers Chrissy

dave06 · Guru

oh I think it was the positioning of the sole wind generator (in my backyard) and not actually a proposal for a wind farm that was opposed, we are in the process of having a wind farm placed just out of Pirie near Horricks pass and I am in favour of it 100% but as we all know these part time operations are not the answer to our long term energy needs which of course must be nuclear

just as a P.S. to my previous post on small wind turbines the reason they are so popular on boats is that down by the ocean even on the hottest and calmest days there is almost always a "sea breeze" more than enough to have these little blokes turning out their rendition of "boundless energy" and they operate at night as well which is a massive bonus, try that with a solar panel

take these little cuties inland and they quickly become becalmed and are really not happy little campers at all

-- Edited by dave06 on Sunday 29th of March 2009 12:44:54 PM

Wombat 280 · Guru

The wind gennies they fit to yachts are great when at sea and you can't hear the bugger over the other noises in the rigging at night ,

Try sleeping on a boat in a marina when the wind gets up and there's about 200 of the little buggers howling away all producing a max 2 amps each sounds like the howl of a banshee

dave06 · Guru

oh they produce a lot more than 2 amps, the modern mini wind turbine is a marvelous thing they can produce between 48 watts/4 amps for a small model and up to and in some cases beyond 300 watts/25 amps, they are however not cheap starting at roughly $1300

they can be veiwed here just one example but there are many others on the site

http://www.energymatters.com.au/aerogen-lvm-212-12volt-48watt-wind-turbine-p-509.html

DubDub · Veteran Member

There seems to be a "Miss conception" on this thread that wind generators go 24/7.Not Quite right.The wind dosen't allways blow me matey.The good thing about the one Dave wants to install at home is ,at 60ft wide,it dosen't need a fast speed of wind to generate,Airex and simmilar marine W/G's would not work effiecently at slow wind speeds.

Mike & Judy,Ya mate sounds just like most yachties,and so we all should be,trying to squeeze every last drop of energy that we can out of nature,be it,power up/temp down.Some esky's are rated,EG..4 day,7 day,whatever the days are that it will keep ice.I'm sure it's all a matter of thickness/type of insulation it's made of.If his refridgeration is a normal evapouration cooling system,I would suspect that too much insulation would tend to freeze things up a bit over time as that system is constent.With a compressor type,it just means the compressor would not have to turn it'self on as much or for as long as normal.If ya mate has a compressor type and runs it off battery banks,I know something that will reduce power usage by about 70% without moore insulation.It envolves turning a chest freezer into a fridge basicly,everyone knows how small a "Tuckerbox" freezer is,The small one,NOT, the larger ones.Although it works on both.If ya interested PM or Email me.Just give me a day or two cause it's on my PC somewhere,but I can find it.

Glenn.

dave06 · Guru

yep you are right the turbine only makes sparks if the wind blows and the solar panels only make power when the sun shines and the gennie will stop if it aint got fuel, everything has its drawbacks, unfortunately the law of conservation will last forever, dont get nothing for nothing

Basil Faulty · Guru

Ah Cooling..... Years ago when I had a boat on a mooring it had a bilge pump that was powered by a pendulum that swang backwards and forwards with the rocking motion of the boat. This kept the bilges pumped dry thus allowing me to remain cool when I had to go aboard and not start the Armstrong pump.....

twobob · Guru

I know I said wind is 24/7, and agree it is not, I think the point was only to show that you (potentially) only need one third the wattage from wind to get the same of solar. All alternative energies have limitations or practical considerations.

They are worth considering, and will need "tweeking" to get the best out of them. Thats why it is difficult to go past mains power. Most of the pratical alternative setups that i have had to do with and seen, have a generator backing them up.

Most of the posters I have seen and read, seemed to "want" more power or reliable power. I for one, would come from the opposite end, and say, what can you do without.

thats like insulation. The better the less power used, but even that is limited to its practical use. Opening the door too often, will fault even the best insulation. Having the fridge partly filled, is similar, as opposed to full.

As for fridges, maybe its the time (and place) to say - what do you really need to have in there. Its not like at home where you bulk buy and therefore have things in there for months on end, going out of date, and never get used in some cases. If you are travelling, then should you not pick up your needs as you go. i know there would be a load of arguement re this, but think on it.

On Dub Dubs point of converting a freezer to a fridge, thats easy, just change the thermostat to a fridge one. They set the temp for cut in and cut out of the refrideration unit. The downside is you may end up with "short cycling" and therefore use more power than you save, in pratical terms.

dave06 · Guru

I agree 100% I try to cut down to the essentials as well powerwise and find that I dont need much at all, we all know what you were saying when you said "24/7" and understood that was only when the wind blows,

Basil I find on many of my boat trips that I must have one of those automatic internal pendulum operated bilge pumps, I seem to empty my scuppers on a regular basis when the sea is rocking as well, never mind it attracts the fish

DubDub · Veteran Member

twobob wrote:

I know I said wind is 24/7, and agree it is not, I think the point was only to show that you (potentially) only need one third the wattage from wind to get the same of solar. All alternative energies have limitations or practical considerations.

They are worth considering, and will need "tweeking" to get the best out of them. Thats why it is difficult to go past mains power. Most of the pratical alternative setups that i have had to do with and seen, have a generator backing them up.

Most of the posters I have seen and read, seemed to "want" more power or reliable power. I for one, would come from the opposite end, and say, what can you do without.

thats like insulation. The better the less power used, but even that is limited to its practical use. Opening the door too often, will fault even the best insulation. Having the fridge partly filled, is similar, as opposed to full.

As for fridges, maybe its the time (and place) to say - what do you really need to have in there. Its not like at home where you bulk buy and therefore have things in there for months on end, going out of date, and never get used in some cases. If you are travelling, then should you not pick up your needs as you go. i know there would be a load of arguement re this, but think on it.

On Dub Dubs point of converting a freezer to a fridge, thats easy, just change the thermostat to a fridge one. They set the temp for cut in and cut out of the refrideration unit. The downside is you may end up with "short cycling" and therefore use more power than you save, in pratical terms.

Spot on Two Bob,What ya can do without is the #1 priority allways,aquirering the optimum output for the system you use is #2. The person that designed the electronic components to convert the freezer to fridge idea was trying to optimise his battery power usage that was supplied only by solar power.(He's trying to get as low as he can on the overall scale of things on power usage)Fridges that open outwards loose moore "cool"than ones that open upwards,fact.Loose less,use less power to cool no matter how ya power it.Not many fridges on the market like that though.If short cycling was so bad on power usage,coles and woollies wouldnt have open coolers and freezers to start with.Granted thier only useing grid power,but the principal still applies.With "Really"good/extra insulation and a fridge designed to apply it's self to thermal dynamics and power usage moore adequally,surely,in the long run it would be moore benificial and economical to someone not conected to the grid 24/7(No pun intended)

Glenn.

DubDub · Veteran Member

Now lets hope this link works http://mtbest.net/freezer-to-fridge-thermostat.html I have a better link but it's in my puter some where and I carn't find it,still looking.This obviously dosnt work on a fridge useing gas.If ya have one running off a battery bank,charged by either solar,wind or alternator then it will suck less power out of the bank.A small chest freezer would not take up much room in a bus/motorhome.Granted this probably isn't too practical for the average G N,but it works .

Glenn.