Cruising yacht

22nd September, 1996 GREG & MOIRA

“DESTINY III”

Dear Malcolm,

As our ICEER fridge / freezer has been in service for over a year now, we thought we would drop you a line to let you know how it has been preforming compared to the engine driven system we had before. Well, there really is no comparison! We found the daily routine of running the motor for an hour or so is a great nuisance. It seemed as if our whole day had been planned around it. Now, with the new fridge, we can leave it unattended for as long as we like, without any external power source, and return to find it as it was left. A quick calculation revealed that the solar panels supplied by you, will pay for themselves within 2 years because of the greatly reduced engine running costs. On going maintenance costs associated with the engine driven system, such as regasing due to losses through rubber hoses, are avoided by your fully sealed system. Hot weather dictated that the engine be run more often and this only added to the already high cabin temperature. The new fridge maintains very constant temperatures, typically between -13 to -16 in the freezer and between -2 to +4 in the fridge. This could not be said for the old freezer which, probably due to poor design and insulation, would range for -20 to 0 on any given day - unless we ran the engine every 5 hours - no thanks! During last summer we had a week of high temperatures in the mid thirties and the new fridge took it all in it’s stride - despite us diving into the freezer quite often for ice cream! We have noticed over the last year that batteries are fully charged again by around

10 O’clock in the morning (in fine weather). There appears to us to be perfect marriage between solar and d.c refrigeration. As the days get longer and hence hotter, the fridge uses more power but this is offset by extra power generated by the panels. We now realise that our two B.P. 75 watt panels are somewhat of an over-kill for running the fridge. After a week of rain the batteries have recovered full charge after only 2 days of clear skies. Realising that we are throwing away power in fine weather, with the help of the plasmatronics smart regulator you supplied,we have calculated we could produce up to 20 litres of water a day from a desalinator by utilising the load dump facility of the regulator. this has yet to be proved in practice, however. Another obvious benefit , not only to us , But to everyone else in the anchorage, is the total absence of noise. So quiet is the new fridge, that our electronic wall clock is louder! Nor can we detect any electrical interference emanating from the fridge. Considering the new fridge is slightly larger, has a real freezer, and is a lot more accessible then the old unit, we now feel we are well and truly in front.

Visitors aboard often comment on how large the fridge is, for a 35’ yacht. With a 30 litre freezer and a 115 litre fridge, they are always amazed that it is powered totally by the sun. I guess we are starting to take it for granted that this fridge is used just like a domestic one on mains power. As we live on the boat, the fridge is constantly being used. We buy our drinks in bulk and the fridge is topped up every couple of days. Warm leftovers are often put in, and on top of this, we have become known for the coldest beers around! Other D.C. fridges we considered relied on an aluminium cabinet being exposed to the air, but it did not seem right to have an expensive teak fit out with an ugly aluminium box sitting in the middle of it. Even aluminium on the inside leaves us a little cold. With the new fridge, we really appreciate the smooth gelcoat finish with large radius corners, so easy to keep clean. No rivets, pipes or anything to get caught on and no sikaflex corners, which seemed to cultivate mould. Again, just what you would expect in a domestic fridge, but not in a marine one. There is surprisingly little ice build up in the fridge despite the number of times it is opened each day, which we can only put down to snugly fitting lids and seals. Ice cream (which is hard enough to bend a spoon), left over from last summer is still smooth and creamy six months later.

You may recall I asked you to install an hourmeter with the fridge so we could calculate exactly how much power the fridge is using. To be perfectly honest with you, we were a little skeptical that the performance figures you quoted were obtainable. Sure, maybe these figures could be achieved under a controlled test conditions, but what about in the real world? Being a technician by trade, I set about taking accurate voltage and current readings every quarter hour while the fridge was running, over the period of a week (yes, I even got up during the night!). over this period, I calculated the average current to be 2.26 Amps at 24.78 Volts and power consumption of 56 watts. My findings are based on these figures and weekly readings from the hourmeter which I take every Sunday night at 10 o’clock. I have tabled the results of these readings.

As you can see, these figures are quite impressive and are actually less then you estimated. I could easily run this fridge with only one 75w solar panel (if they made a 24v panel). By the way, I did some test to compare flat mounted panels with panels mounted in such a manner as to allow us to track the sun. On the test day the flat mounted panels achieved 25.14Ah (2 x 75w B.P. @ 24v or 1 x 75 w B.P. @ 12v) while the same panels achieved 37.38Ah when tracking, an increase of 50%. This may be of interest to some of your customers who lack sufficient deck space or funds.

I have received some weird looks from people when I reply to the inevitable question - “How much did the fridge cost?” - I do not look at the cost of the fridge alone, but rather the whole working system. When you consider the larger volume, half the number of solar panels required, high standard of construction and finish, your prices become very competitive.

When we dismantled the old fridge, the polyurethane insulation felt as though it was quite dry. It was only when we felt the weight and the fact that is was dripping on the floor that made us realise the foam was totally ruined. We now understand why you will not sell a kit, but rather a complete unit. While the new fridge was being installed, a friend generously loaned his three-way 45 litre camping fridge to us. Fortunately we were able to run it on mains power as upon reading the specifications we found that this little fridge consumed 190Ah per day on 12v and we never saw it get any colder than +7 degrees! We never ran it on gas to see how much it consumed, because it has been our experience the gas fridges become very ineffective when subjected to movement such as the motion of a boat.

During the week of very hot weather I mentioned earlier, I had the opportunity to appreciate how well your fridge control system works. On a friends boat which has an identical danfoss compressor, but no control system except for a thermostat, the fridge ran constantly for about 4 days in the heat and then finally expired. This reinforced the generally held view that 12 volt fridges do not work in the tropics. Once your fridges become more well known, we are sure this attitude will change.

Although we have bought many consumer items in the past that we have been happy with, we have never been totally satisfied as to take the time to write a letter of appreciation. The concern you showed by catering to our every whim and ensuring that the fridge preformed to our complete satisfaction, both before and after installation, did not go unnoticed. It became apparent to us you have a great deal of pride and belief in your product and this is obviously reflected in the superb fridge we now have.

In appreciation of all this. please feel free to use this letter for any advertising you may do. We wish you every success for the future.

Regards

GREG SCHWARZ

MOIRA TODD