Air Conditioners – Keeping the costs down
Like most things, the innovative have discovered how to keep themselves cool at a fraction of the cost of an installed split air-conditioner which uses a compressor and refrigerant. Be warned though, depending where you purchase your hardware it can rack up more than a hundred dollars like it did me.
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The Instructables
Here is a link to a cooler which uses cold water to cool down your environment. Although it professes to be a spot cooler I did make one and with leaks and all it cooled the temperature down by at least 5 degrees C (31C to 26C) in our living room. Admittedly I use a larger fan, diameter 40cm (16″), more piping around the outer area, piping is 8mm diameter (5/16) and I used glands to seal off the ice box. I could not get the plastic pipe to seat properly against the copper pipe which created one leak which subsequently was fixed by rolling two turns of insulation tape around the circumference of the copper to make a tighter fit for the plastic pipe.
Although one can pick up a 2nd hand A/C unit with warranty for about 200 dollars the biggest problem here is the running costs – electricity isn’t cheap and I would need an 8 000 BTU to 10 000 BTU air conditioner for our living room Mild climates don’t always call for drastic means but anything above 30 degrees C does mean a bit of discomfort. Unfortunately I would have loved to have tested this ‘alternative’ means to cooling down the air in our recent 40 degree C bout of weather but like all mother of creations, we do the deed after the fact.
Was it worth it? I think using the same principle with a proper evaporator would have being much more efficient. This will be my next project. Secondly, whether running copper piping into the ice box would make much difference is debatable – I left that out. Further experimentation on this unit in future – it’s an easy build and fun too. Insulating the plastic piping is very important. Power consumption – water pump is a ViaAqua VA-470A 1800 L/Hr or 800 L/Hr at 1.4m 60W and the fan is driven by a 70W motor. Locally we pay about 16c kW/Hr so we are looking at about 2c per hour or over a month continuous, 15 US Dollars. Of course the freezer had to make ice so this would have cost a few dollars more all in all, a much cheaper alternative to a 3kW air conditioner. As efficient, no.
A Water Evaporator System
I liked this post on the Instructables – maybe a bit more sophisticated than the average project which means more time and money but a solid design and one which will work well. Go here.
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and of course, last but not least, using a home made evaporator come water cooler: http://www.instructables.com/id/Free-Air-Conditioning/?ALLSTEPS
The DIYer forums are always entertaining. I commented on your previous article ‘Understanding your refrigerator system’ – possibly over simplified because your refrigerant or at least the boiling temperature of refrigerant is really the core to your system I had to add in my two pence worth and that is heat pump theory does not always involve a compressor, the ‘heart’ to the system. When a designer puts pen to paper what should always be THE most important factor in refrigeration design is how the installer views it. As you state, refrigeration systems of late are all dated, techniques used are old hat and although the manufacturers state that they are using the best and latest techniques, the BTU is a power unit, originally derived from steam engines (I stand corrected – that’s what I was taught). Leaving all the theory behind us then – cutting costs down I do think that ice is a wonderful means to cool down your living or office area. What did it cost to produce that ice? We think in terms of heat and watts and consumed power to warm our living area – in cooling down the living area it costs us the same, no matter how we look at it.
Using a home made evaporator and utilizing underground water at 10C is a clever idea – no matter how one looks at it.
Here is the BIG question – when we build a house we build a foundation, put up walls and then a roof. A hunter’s breakfast when I was a growing lad was a a meal made on a fire and then placed into the ground to continue the cooking process, the ground after all has really wonderful insulating properties and really does a wonderful job. The pre-heated meal cooks itself. The heat dissipates slowly into the surrounds.
Why not build a house under the ground – doomsday preppers are thinking and doing it. When one buys property does the title deed state the square area or the depth. When we want a larger house we build a multi-storey building. It’s impressive – I think building below the ground is more impressive. Temperature control is also much easier is it not.
Know your ground and build there – who knows, if you build low enough you have free access to water, exceptional thermal insulation, the walls are already there (to a degree), you have safety from the elements and what is even better is that your rates ‘should’ not go up. I find it interesting that 60 years ago we were thinking on that level – 60 years on forgot that the best way to combat temperature stresses is to insulate and use the environment to our advantage.
Anyone care to comment?