Tuesday, June 9, 2015

Thoughts on alternative cooling

Yesterday, as I worked, hanging the bedroom door, sweat was dripping off me. That had me thinking more about cooling systems. Now, as you probably know, there are two main types of cooling system in use in the USA. The first is the ubiquitous air conditioning unit. These have been around since the 1930s.

An air conditioning unit works exactly the same way as a fridge or freezer works. Essentially there's a huge loop of aluminum tubing with a pump that pumps a refrigerant gas around the loop. On the far side of the loop from the pump, the tube has a constriction that allows only a small amount of gas through. This has the effect of creating high pressure on one side and low pressure on the other. A compressed gas emits heat while an expanded gas absorbs heat. You can see where this is going! The tube section with expanded gas runs into the fridge\freezer and the tube section with compressed gas is behind the unit. All this pumping to pressure uses a lot of electricity.

The second type of cooling system is known as a swamp cooler. Effectively, its hanging a wet towel in front of as fan that's blowing on you. That works because as water evaporates, it takes heat away, leaving the remaining water cool.

In a humid climate such as South Carolina, a swamp cooler is less effective however I have come up with a work around to that issue and to the fact that swamp coolers add water to the air.

My solution is to pass aluminum tubes through a water container. Water is allowed to evaporate as normal, keeping the body of the water cool. Air is passed through the tubes and of course the water absorbs the heat of the air. The air coming out is cooler.

This won't be as cool as a compression air conditioner and does need several things. It needs to be filled regularly with water, it needs to be kept out of sunlight and it needs electricity though not as much as a compression unit.

This is what I intend to build for the bus, when I get into the electrics. The other thing is an extraction fan to remove hot air from the bus.

Other than thinking about cooling, all I've done is to visit Lowes and Home Depot for more supplies and to use the new hole saw to cut through the first skin of the side door in preparation to install my second lock.

Another thing I did was to start investigating a new shower base. The base I bought for $40 from the dodgy guy advertising on Facebook looked OK when I bought it but has since developed lots of cracks. Clearly it was cheap because it was trash that I'm now going to have to find some way of disposing of. This happens every time I buy used stuff. It either needs far more work to bring it up to an acceptable standard than anticipated of its absolute trash that I end up having to take to the dump.

Thus far, it looks like Tractor Supply might have something good. Feeding troughs and concrete mixing baths look likely candidates. At 2 feet by 3 feet, they'll fit the available space nicely.


  1. Lot's of people use the feeding troughs in their showers. One lady even used one for a bath tub.
    I have one question for you, if you hate Lowe's so much why do you keep going back? I've just started reading about this build so excuse me if you have explained all this in another post somewhere.

  2. Simple. I hate Lowes because of their endemic dishonesty. I've been lied to by various tiers of Lowes from store level right through to corporate. I use them because it's 6 miles to my nearest Lowes and 12 miles to Home Depot or Tractor Supply. At the end of the day I could take the moral high ground and refuse to use them. It wouldn't have any effect on their dishonesty though and it would hit my pocket book by 12 miles each trip. As long as I don't need Lowes version of the truth to be right, I'm ok. I deplore them but I'm not going to spend more money than I absolutely have to.