Air Conditioning

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These were engineers, and not the kind that brags about all the stuff they had installed.

You have to keep it clean, it's certainly not an apparatus you just switch on in spring and switch off in fall. But it doesn't need more than 2h of my time per season.

Evap coolers only work if the humidity is low on very hot days.

--
Regards, Joerg

http://www.analogconsultants.com/

If the humidity 70% any evap pre-cool is useless. But most of the really hot places in the US (CA inland, AZ, NM and so on) show very low humidity when it is hot. Most of the time the air out of our evap cooler is well over 20F lower in temperature than what goes in.

Mold growth: None. At least not here.

--
Regards, Joerg

http://www.analogconsultants.com/

You do understand evap cooler refers to the indoor air side- and not that pre-cooler kluge? Is that what you're even talking about?

Sure I understand that. And both work. Both also require more maintenance than a regular plain old A/C but it is a small price to pay for the savings and eco-friendliness of evap colling or pre-cooling.

One of the issues with evap cooling of any kind is that, like regular A/C, the "technology" is from the Flintstone era. I mean, what would it really take to have a uC-controlled regular dump function for the basin? Or a pad flush? That takes at least half off the total maintenance hours per season. But I guess an 80C51 is already too high-tech and too much to grasp in that industry. Usually the number of smart control features on those things is zip, zero, zilch.

--
Regards, Joerg

http://www.analogconsultants.com/

power

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temperatures,

I know a power engineer (was the VP of advanced projects in a rather large power company) who believes in "Watt Savers". He has the 60-Minutes interview to prove it. ;-)

You need to work on it more often than that to make sure you don't get Legionella in there. That doesn't even start to talk about early failure.

We have half the necessary requirements. Unfortunately the low humidity part isn't it. I'd likely cut another month or two of AC use each year if it weren't so humid. We only run it (cooling) about 3-3.5 months now.

Most? What about TX to DC, FL, to Chicago?

Not believing it.

and the same mcu could control a electric evap valve and a variable frequency drive for the compressor to keep keep the system working at the highest efficiency

-Lasse

power

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temperatures,

80 degrees and humid isn't indoor comfort in my book. Of course I'm from the Canadian Riviera.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net

power

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Well, there are always a few nut cases even among engineers. But only one out of hundreds.

I clean the thing on the inside at least once a month. Takes 10min, at the most. If this was a problem then we'd see lots of legionaire's disease cases in the hospital around here. Because lots of people have their cooler on the roof or under the eaves. Which means it's hard to get there, which in turn means people simply don't go up there. They just run them flat-out all summer sans cleaning. Yet not disease uptick AFAIK. I am certain the government would have stepped in if there was.

Evap cooling is not new. It was used by the Persians (Quanat Cooling) in biblical times and they didn't catch legionaire's disease either.

So what is it that should fail? Those things are fairly simple. Everything is big and pretty robust.

years

Then evap cooling is unfortunately not for you. There aren't many places in the south-eastern US where it would work.

--
Regards, Joerg

http://www.analogconsultants.com/

Yup. But progress moves at a snail's pace in that industry.

--
Regards, Joerg

http://www.analogconsultants.com/

Some parts of TX and much of the midwest would benefit from it. Of course not the south-east part of the US. Fact is, we could decrease the power crunch our country faces in summer, big time.

I can't help that. Mold ain't there. I could snap a photo of the inside, except my Nikon is busted (reason for the digicam thread) because of a mechanical engineering blunder. It's all spiffy and clean in the machine.

--
Regards, Joerg

http://www.analogconsultants.com/

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Most of the days it's 70F to 75F. I like it more humid even though I grew up in a similar climate as you (Germany). Regular A/C with it's vey dry rushing air gives me the sniffles. In companies it can give me a headache after a while because of the large percentage of stale air that just gets sloshed round and round. The evap cooler pumps in a complete new charge of fresh air several times an hour.

It becomes quite obvious when watching little things. For example, when one of our dogs "let's one rip" the stench would linger for minutes. Now it's gone in seconds.

--
Regards, Joerg

http://www.analogconsultants.com/

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want

Brothers, too (though not in the hundreds ;-).

I'm quite sure they regularly, if not constantly, disinfect them, something that cannot be expected of a homeowner.

Neither is Legionaire's (however the name might be). It does require a fairly precise combination of conditions, which are available in swam coolers.

Water, crud, and distillation, around the equipment. It increases the complexity of the system. All things that aren't wanted in an air handler.

years

From Houston to NYC is a *LOT* of area. For those of you living in a desert, go fer it. The augmented AC doesn't seem to be a winner, though.

Far Western TX, perhaps. The rest of the state, no way. The areas of the Midwest where it would be useful don't need AC at all. Swamp coolers certainly would be a waste in IA, IL, IN, OH, and South.

I find that incredible; standing water with no mold.

problem with the fancy electronics power controls is this...

they may optimize efficiency and save you $10 to $20 per month, but then comes that lightning surge and you get the $500 bill for the repair.... wipes out 2years of savings in a flash.....

a big ole contactor would shrug it off...

Mark

[...]

These _are_ homeowners.

What's complex about an evap cooler? There is the pump, there is the big squirrel cage fan, big ones have a separate motor and belt. That's pretty much it, the rest is all stationary stuff that can hardly break unless uncle Leroy backs the tractor into it.

be

years

The real America starts west of the Rockies ...

--
Regards, Joerg

http://www.analogconsultants.com/

[...]

There's a whiff of chlorine in our tap water. Which is why we filter it. Also, you can get soap bricks where you break off chunks once in a while and toss it in there. Prevents gunk build-up, algae and stuff. But it does leave soap turds on the pads which is why I rather clean every few weeks.

AFAICT algae build-up is much more of a concern than mold.

--
Regards, Joerg

http://www.analogconsultants.com/

Swamp coolers are *not* common. If you think the government is going to save you, all I can do is laugh.

You were talking about a swam cooler/refrigeration hybrid. That is

*necessarily* more complicated than either.

be

years

part

...and runs East from there, to about Pittsburgh. There is no way in hell, Kalifornika is "real America".

You couldn't convince anyone to the right of Nancy Pelosi that Kaliforika was real in *any* way.

In a control room at work we have an Air Conditioner, Mitsubishi I think, that is supposed to be more efficient than geothermal. There is an outdoor unit with an electronic control system and 4 indoor units that consist of coils and fans. Each indoor unit has 2 copper tubes for refrigerant in and out. I don't know much about the system but I think it's supposed to be variable BTU by using Mitsubishi variable speed drives. (fans, compressor, or both?) That's where I got the idea about controlling the compressor with an inverter VFD. I was thinking of controlling the speed to adjust temperature instead of cycling on and off. With my own controls it would be easy enough to put temperature sensors on all the coils, prevent frozen coils, perhaps even pressure sensors for the high and low side if beneficial.

On the other hand, I've been reading up on some of the newer window units and they have features where they go back to their previous settings in the event of a power failure. Also I have noticed some of the smaller window units have a better EER rating than the larger ones. Maybe It would work well to use multiple smaller window units with energy saver mode (off when not cooling) set so that 1 unit runs most of the time, other units come on at higher temperatures, so that at least 1 AC runs most of the time during the hot weather, not cycling a single large unit on and off.

Even if I do the multiple window unit thing, it would be nice to have a central control system so I can balance out the hours each AC unit runs. Something like each day running the low hour unit continuous and cycling the others as needed.

RogerN