New Air Conditioner Time

[twintubdexter]

an ever so slighlty off-topic quesion

Here's one for all you cooling Xpurts...My friends across the street have a 1,500 sq foot home with a through-the-wall evaporative cooler, professionally installed when the house was constructed but a window unit nevertheless. These guys insist that on a typical 100 degree day the unit maintains a 70 degree temperature throughout their home. I think this is bunk. How can water, heated from 100 degree outside air and circulated over pads come out 30 degrees cooler on the other side? I understand the principle of evaporative cooling and how it makes you feel more comfortable. Logic tells me that even if the air was that much cooler temperature-wise it would not maintain 70 degrees throughout the house. Because of the size, my house requires 2 central systems...not huge since anything over 2,000 sq ft here in the desert does. I have no evaporative system and they are constantly telling me "poor Joe, he's forced to use those expensive air conditioners." Actually they're fairly new American Standard units and very efficient and my house and attic area are super-insulalted.

 

[mieletag]

Actually, the evaporative cooling does work, but the relative humidity must be low enough for the process to work correctly. When the hot dry air enters through the water soaked pads, a little bit of the water is evaporated, taking away heat with it. That is why there is generally a constant makeup water supply available, usually a float, to replenish the evaporated water. But, I have been hearing for several years now that the dry Southwest is getting more humid than it was years ago because of lawns and swimming pools and people just using more water in general, and swamp coolers are not quite as effective as they once were. As the latent load increases (humidity), the sensible load (dry bulb temperature) is not as easily controlled.

 

[nurdlinger]

Swamp Cooler conventional wisdom...

...says that the device can drop the incoming air temperature by 20 degrees F. I ran one for 30 years and that seems about right. So the 70F claim with 100F outside air makes me skeptical. I had recently to replace the 23 year old heat pump on my roof, and I took the opportunity to have the swamp box permanently removed at that time. When I was younger I could get up on the roof and service it myself. Can't do that anymore. Also, the cooler was 28 years old. Exterior is stainless steel and has stood the test of time quite well. (no leaks!) However all the inside items like the squirrel cage fan housing and bracing is rusted to pieces. Parts are still available and it could be restored to service for a few hundred bucks, but people for hire to service it every spring are getting more scarce/more expensive as time goes on. It provided very good cooling. Cooler start up day in the spring was the best day of the year. The scent of the new aspen wood pads was delightful.

 

[arbilab]

* At 32 °C (90 °F) and 15% relative humidity, air may be cooled to nearly 16 °C (61 °F). The dew point for these conditions is 2 °C (36 °F).
* At 32 °C (90 °F) and 50% relative humidity, air may be cooled to about 24 °C (75 °F). The dew point for these conditions is 20 °C (68 °F).
* At 40 °C (104 °F) and 15% relative humidity, air may be cooled to nearly 21 °C (70 °F). The dew point for these conditions is 8 °C (46 °F).

(Cooling examples extracted from the June 25, 2000 University of Idaho publication, "Homewise" via Wiki.)

Calculations of evaporative coolers at several inlet temperatures and dewpoints. We see that 90 to 60 or 100 to 70 are indeed possible in dry areas. I have used 3 swamp coolers, in Colorado, San Jose, Palmdale. Best not left on much after sunset, they get TOO cold.

 

[spookiness]

shopping again

I got a Frigidaire LRA067AT7 6k BTU early this season, and I'm not crazy about it. Despite various high ratings, it is noisy, the compressor engagement/disengagement is too abrupt, and experience with other Frigidaires leads me to believe it will eventually become a mold factory.

I might try an LG. There is an 8k LG unit in my housemates space, but I haven't spent much time around it. I am wary of Haier and other off-brands, but willing to try something else.

 

[launderess]

I guess after getting all strapped up to get into that outfi

Especially if she had on a Playtex rubber girdle!

Just getting into the thing could cause one to work up a sweat.

*LOL*

 

[whirlcool]

Do women even still wear girdles? I haven't heard of that in a long, long time.

 

[foxchapel]

Do women even still wear girdles?

Yes, some do, sort of. The new millennium version is called Spanx.