Air conditioning for your pet mouse
Jack and Dah have a goal: no house air conditioning.
Air conditioning is notoriusly inefficient in Thailand, with typical split room-size air conditioners churning out 12000 BTU per hour (3000 watts) of cooling per room, mainly energy spent on cooling sun-heated walls and vaporizing moisture that freely enters the room from outside sources, all at a cost equal to 35 percent of a Thai college graduate's salary. Tankers of oil steam into the Gulf to meet this wasteful demand.
And of course with the light, leaky construction of a traditional Thai house an off-the-shelf machine would be even more inefficient.
So...while hanging around the pub one day I set out to reinvent the air conditioner.
Let's start not with a 3000 watt machine, or even a (say) 300 watt machine that would be arguably sufficient to cool Jack and Dah when they are sleeping. Let's start with the bench machine above, which I built for a couple of hundred baht, a one-watt air conditioner, which meets the following specifications:
cooling capacity (mostly latent): 1 watt
condensate, cc/hr: 1
unconditioned air water vapor entering machine: 20 g/cubic meter
conditioned air water vapor exiting machine: 8 g/cubic meter
Operation of this machine requires about 3600 joules of energy per hour, which can be easily provided by only about 10 grams of ice.
The question: can we effectively scale up, say by a factor of about 300? This would require about 3 kg of ice per hour--seems doable.
Saturday, November 3, 2007
A one-watt air conditioner
Friday, November 2, 2007
Aircon fantasies
In times of general retreat I spent hours fiddling with air-conditioning ideas. Solar powered desiccants. Micro air conditioners like they used to cool yachts and space men and NASCAR racing drivers. I went to the annual southeast Asian air conditioning trade show at the Sirikit convention center. Eager Chinese salesmen filled my arms with lavish brochures. The brochures showed their company president, tan, fit, and shrewd, perfecting his golf swing. China was clearly the future of air-conditioning manufacture.
But what I wantedI couldn't find. That was, a device that would condition air for a couple of people, not cool a big leaky overheated Thai room that delivered 2000 watts of heat from walls heated by the afternoon sun and steamy outside filthy air through window framwes that didn’t fit right. I knew he was on the right track when I went to visit the Carrier office in Bangkok. They somewhat reluctantly sent an engineer out to talk to this fahlang with the short pants milling around the front desk. Could they offer small units, maybe 5000 btus or less, asked I?
"What you want for?" the engineer asked, his eyes narrowing suspiciously.
“For small room, maybe twenty, twenty five square meters.”
The engineer whipped out a calculator and pecked in some numbers. Multiplying something by twenty five. No wonder people are annoyed by engineers, I thought to himself.
"Twelve thousand. "
"Twelve thousand what, for what."
" BTU for room."
I said that I was amazed, amazing thailand, I said, that he could do this so quickly. He must have a very good college degree. I thanked him for his time in a rather exaggerated way that he hoped conveyed the general idea. This was a Thai trick he had learned.
*********************************
I thought some more on this subject that I was clearly thinking about too much.. This is what I am looking for, I thought:
The system would cool a large fahlang body, and maybe Dah too if Jack could ever get it together with her. It would cull a small space that was reasonably protected against radiant, convective heat transfer and moisture infiltration, either convective or diffusive. Maybe like a tent. I drew a sketch.
The air within would be dry, say 40 percent RH but not too cold, so maybe there would be some heat transfer between the incoming and outgoing air. The capacity would be only say 500 watts or 2000 BTUs per hour, half the size of a small US style window unit, 20 percent of the one that Mr. Wonton said was necessary because it was the smallest the Carrier company made. The electrical savings for say six hours of operation of a 2000 btu unit would be a dollar fifty a day. Half a million air conditioners were bought in Thailand every year. The space to be cooled would be small, maybe 25 cubic meters altogether, and the envelope would serve as a mosquito barrier as well. The air would be conditioned air would be ducted into the space silently.
And wouldn’t it be nice to power the whole thing with exactly that dreadful stuff that was causing the whole problem, the 1000 watts per square meter, that would be 36 kw of power, of sun power burning down on that hot red roof? Maybe putting all that heat into the ground or say a lithium salt solution or some ammonia like the old days under the house or hidden away in the garden and some of it into the cool 26 degree water that came in off the street so the shower would be nice in warm in the cool season when the sky is clear and the solar at a maximum?
They would call it the "Ron Swelters Quarter Ton Aircon Machine", dedicated to His Majesty the King who had shown a keen interest in energy savings, and also to Doctor Carrier who invented the first air conditioner to cool the fevered brows of malaria victims but who had been swindled out of his rewards by John "Ice King" Tudor. In the year 1831, it was.
This was getting good. I ordered another pint, it was three minutes before seven and the price would double if I didn’t, the waitress told me so.
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The following night I had dinner with Jack and Dah. I told them all about my air conditioning ideas.
"Oh, Khun Jack, that very good. "
Jack thought this would be a good time to sort of pop a question.
"You know, Dah", he said, "we have to make an important decision. W can do it with only 1000 btu. But maybe I should get extra, maybe 2000 btu. Just in case maybe things different in the future."
Dah considered this.
"I think you and Ron know best about this. We need more money in account."
Thursday, October 25, 2007
End of the rains?
Could this be it, the end of the rains?
Last weekend a great flood in our neighborhood, a day confined to home with two feet of dirty water in the streets, local kids swimming happily in the sewage. Dek Sa-lum, says Auntie Porn, our Isan cleaning lady.
Now this week the days feeling cooler in the morning, no more than a few weak drops of rain in the late afternoon. It just feels different. Notice the wind heading from the west to east, then changing to the north, this was the beginning of the different feel. Dah says that winter has come. (Though the night temperature of close to thirty is still a little warm for this fahlang.)
Monday, October 1, 2007
Index of pages
| A long way from home | 1/1/2007 |
| black hole | 1/1/2007 |
| Greasy black dust | 1/7/2007 |
| 2007/07/first-night-tropical-paradise.html> | 1/10/2007 |
| by Ron Swelters " align="left" height="17"> 2007/07/that-april-thrill.html#comments> by Ron Swelters | 1/10/2007 |
| 2007/06/here-is-my-story_25.html> | 2/28/2007 |
| 2007/06/same-heat-every-year.html> | 3/1/2007 |
| Tropical Cool: How was it for you? | 3/6/2007 |
| Tropical Cool: Hot roof unmitigated(revised) | 3/9/2007 |
| Tropical Cool: Solar-heated concrete roofs | 3/10/2007 |
| Tropical Cool: Foiled by the foil | 3/11/2007 |
| Tropical Cool: Carrier's magic chart | 3/12/2007 |
| Tropical Cool: Tour the world's most uncomfortable cities! | 3/15/2007 |
| Tropical Cool: Why so hot at Don Muang? | 3/17/2007 |
| Tropical Cool: Keeping cool without sweat | 3/22/2007 |
| Topical Cool: Bangkok 's lovely breezes | 3/23/2007 |
| Tropical Cool: You probably don't vent enough | 3/27/2007 |
| Tropical Cool: Big open windows | 3/28/2007 |
| Tropical Cool: Fans and turbines for a hot afternoon | 3/29/2007 |
| Tropical Cool: A hat for her apartment | 4/1/2007 |
| Tropical Cool: When will the heat break? | 4/3/2007 |
| Tropical Cool: An escape from romance | 4/8/2007 |
| Tropical Cool: Worst night yet | 4/8/2007 |
| Tropical Cool: A two-hundred foot tree | 4/15/2007 |
| Tropical Cool: Local wisdom, upstairs/downstairs | 4/20/2007 |
| Tropical Cool: How cold that night sky | 4/22/2007 |
| Tropical Cool: Regional heat agony today | 4/24/2007 |
| Tropical Cool: My fan's fan Apr 27, 2007 352 | 4/27/2007 |
| Tropical Cool: Cold exceptions prove the hot rule Apr 30, 2007 298 | 4/30/2007 |
| Tropical Cool: Banish unsightly necksweat! May 08, 2007 320 | 5/8/2007 |
| Tropical Cool: Hungarian attack on US hegemony May 11, 2007 316 | 5/11/2007 |
| Tropical Cool: Are the Thai really different? May 13, 2007 508 | 5/13/2007 |
| Tropical Cool: Enter humidity May 21, 2007 308 | 5/21/2007 |
| Tropical Cool: Thai comfort II (the mysterious orient) May 25, 2007 297 | 5/25/2007 |
| Tropical Cool: Is a hot tin roof cooler? Jun 10, 2007 249 | 6/10/2007 |
| 2007/07/hatless-in-bangkok.html> | 7/30/2007 |
| 2007/07/waning-heat-of-summer.html> | 7/31/2007 |
| 2007/08/hot-tin-roof.html> | 8/1/2007 |
| " align="left" height="17"> 2007/09/old-spice.html#comments> | 9/24/2007 |
| 2007/09/normal-year.html> | 9/24/2007 |
| one watt aircon | 11/3/2007 |
| aircon fanatasies | 11/3/2007 |
| IN the cool of the pub | 11/4/2007 |
| Cool night roof | 11/12/2007 |
| Would you mosquitoes mind leabving | to add from thaivisa |
| Out of Africa | to add from thaivisa |
| Rain and the mud | to add from thaivisa |
| Tropical Cool: The dream and the dread | x |
| Tropical Cool: That April thrill | x |
| Tropical Cool: Hot tin roofs and fahlang sweat | x |
| Tropical Cool: Night heat in June Jun 15, 2007 257 | |
| the air from Isan--november | 12/1/2007 |
| change your perception of (proust) | 11/26/2007 |
| index | 10/1/2007 |