Monday, January 17, 2011

Of Ammonia Absorption Refrigeration & the Like...

It's interesting that I have not written anything here yet this year, not even a Happy New Year. I must be busy. During this season, I do much thinking about snowstorms, power outages, survival etc. I like to think that most bases are covered. I have enough firewood to last me into next winter, so a power outage is really only an inconvenience at worst. Of course winter helps in that the only real electric dependency, Refrigeration, is offset by the fact that it's cold. However, and to get to my point, I'm a little obsessed with the whole concept off "off-grid refrigeration". It's actually a childhood throwback on two fronts. Let me explain, first I remember going to our "camp" in the summer. Routinely, considerable quantities of Soda Pop (we just called it "drink") were lugged to the camp. Sometimes it was Co-op brand tin cans, Pepsi, or even green bottles of Mountain Dew complete with the hillbilly exclaiming "it'll tickle your innards".
 Sadly, it was always warm in the summer, and I hate warm Pop. The best we could come up with was to submerge the glorious nectar along the shore of the lake; not good enough. Secondly, one of my relatives had a summer cottage (we called it a cabin) with no electricity. To my amazement, it had a reasonably sized white refrigerator. How could this be I wondered? Since he was known for trying to pull the wool over my eyes, my unbelief materialized when he exclaimed "it runs on kerosene". When I suggested he was nuts, he popped open a little door in the bottom of the fridge, revealing a circular bluish flame. Crap he was right! It did burn kerosene. Lord help my unbelief !! That was my introduction to absorption refrigeration, and I was hooked. Of course these old kerosene fridges were very scarce and I never ever got my hands on one. With kerosene selling for over five bucks a litre in these parts it's just as well. The alternative of course is ones that burn propane. They use the same technology but they are less messy and an overall better choice. The RV industry has been on to this for decades and delivers accordingly. Both my 1986 VW Camper and my even older 1975 Winnebago Brave are fitted with said devices, and they indeed afford refrigeration without the need for electricity.Even better, they are fitted with both 110v and 12v heating elements that are suitable substitutes for said bluish flame, depending on your needs. You see the system simply needs a heat source in order to work. It does not care where the heat comes from, a propane flame, an electric element? Whatever...
 The only thing missing from the whole equation was the concept of "portability". If one was going camping without aforementioned vehicles or just needed a small portable fridge ??? One option is a cooler with ice, but that only works for a few days at most, and to extend it equals weight and bulk. There's also those popular 12v coolers, but they pull six or seven amps from a battery, and will leave most vehicles dead in an 8 hour day. You could overcome with more battery power, generator/charger, or solar panels, but it gets complex and costly. To get back to my point, my preference is a portable absorption fridge that runs on propane. They are traditionally expensive, but in recent years, Canadian Tire has been selling one. It's regular price is $299 or so and it almost NEVER goes on sale.
 You could easily miss it since it seems to blend in with the other "Mobicool (formerly Koolatron) units that abound. Imagine my shock when I came across an old version of this model on Kijiji for a lousy $25. I rushed out and grabbed it of course. 
The guy told me he never ever lit it, only used it in electric mode. It's top loading, much like a traditional cooler. These things are limited though. For example, this one only cools to 20c below the ambient air temperature. So, well it will freeze things at room temperature, it won't fare so well if the temperature is 30c. The thing that I like about these things is how stingy they are with the propane. A 20lb BBQ tank will run this thing for about a month. So far, I've only used it on 110v to see if the ammonia system was working. I need to put together a suitable regulator/hose assembly before I can test the propane portion, and summer is far off. Test report to come...

IVECO...

 This beauty has been roaming around Central Newfoundland lately. I just grabbed some photos of it for fun...

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