Showing posts with label cooling systems. Show all posts
Showing posts with label cooling systems. Show all posts

Wednesday, May 21, 2008

Summer Hits the High Desert

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It has been simply gorgeous out here today. The sun is gauzed over lightly by wispy clouds, keeping the air cooler than normal. There is a strong wind blowing through, suggesting that Nature is about to bring new weather our way. You never know quite which way she will change, you simply know that there is change afoot.

And I am finally comfortable in pronouncing that summer has hit our high desert. It was barely two weeks ago that we had our last hard frost with temperatures dropping down into the mid-twenties before dawn. That one felt like the last official frost of winter to me, finally! Yesterday, the temperature broke the nineties mark and prompted the annual ritual of reviving the swamp cooler. If you have never lived in arid regions, then you probably haven't a clue about how this odd, simplistic and miraculous item works. If you tried this in Missouri, you would be mildewed from head to toe and sweating even more profusely.

The more dignified and descriptive name for this device is 'evaporative cooler'. The idea is to drizzle water down over fairly absorbent materials in the in-take filters so that air flow will cause 'evaporative cooling'. To bring this idea home, remember back to running under the sprinkler as a child and feeling the breeze bring a goose-bumpy chill as it hit and dried the water on your skin. THAT is evaporative cooling at work!
.The Rat's swamp cooler had been draped over with canvas since last Fall and now the Spring uncovering and resurrection was due. It is a ritual to mark the seasons. Mark found and readied the ladder and, since I am least likely to break the Rat's smallish rafters with weight, I climbed up onto the roof and unfastened the tarp cover. Mark winces noticeably when I scale the metal ladder in my 'construction slippers' (which are basically soft-bottomed moccasins) but I like the real time connection with my footing and the rungs don't seem to bother my in-step at all. This explanation of the 'construction slipper' is really for my U.K. cousin who has asked what apparel might be most suitable during his upcoming visit. The term came about since I have used such footwear forever and for everything, including severe house make-overs. Mark never did get over my use of them and OSHA would undoubtedly faint dead away at the prospect. But what was most hilarious was when I mentioned construction slippers to an old friend who I found again after twenty years and he knew EXACTLY what I meant. "You wear construction slippers, too?!" Sure enough, he sent me a photo of himself building a log cabin and shod ever so comfortably in those versatile moccasins. Great minds and all that, you know, but not recommended for the faint of heart and tender of foot.

Mark scaled the ladder next and siphoned out the slimy residue left over from last year before refilling the sump reservoir and making sure that the make-up water float control was functioning properly.

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Job done! Here is the swamp cooler ready for hot weather action once again. Now you can see that the unit has a louvered intake panel on all fours sides. Behind each louver is a pad of material over which water is drizzled continually by a small amp pump. The big strain on the generator is the start-up of the fan motor, one not unlike your furnace fan but without it, you are not going to get any cooling effect in the living space.

Our regimen is to open the exterior hose bib which supplies the water to the pump and then let it catch up since water will evaporate from the reservoir over night. To allow proper and even through-circulation, we then open a window at each far end of the Rat and make sure to close intermediate windows or at least narrow the openings considerably. Then we make sure that the sensitive computers are not on during the start-up of the cooler. You can turn them on as soon as the start-up amp demand of the fan motor has been satisfied however. The last step is hitting the cooler switch. If the start-up doesn't kill the generator with its demand, you grin and begin to feel the cool relief wafting down from the big ceiling vent ... a glorious relief!

The pros and cons of this unit in our situation:

I suppose we could have gone without any cooling at all and simply lay there sweating and whining incessantly throughout the entire summer but both of us run body systems more suited to Alaska and don't tolerate heat all that well (don't ask us why we settled in the desert - it was just one of those strong emotional things).

With the prospect of only generator power and maybe eventually solar power, standard compressor-driven 'refrigerated' cooling was absolutely out of the question. The electric supply required to keep such a system happy was too great for our situation.

The swamp cooler has much less electrical demand but it is a shameless water hog. I monitored its water consumption through the translucent walls of our 350 gallon water tank. The unit will consistently use almost 100 gallons of water a day during the hottest weather. If you have to truck water in, this is not an affordable option. Fortunately, we have a shallow and plentiful well and can refill our tank as needed.

Just as an exercise, now consider what demands such popular cooling systems would place on the limited water resources of any quickly growing city in the desert. Some new desert McMansions may consume three or four times that amount of water. You can eat up water or electricity ... or just wilt miserably and unproductively in the heat. Decisions, decisions, decisions ... as always.
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