Evap Cooling. Please Help!

[bob w]

Forced Air=ducted.



(Forced air systems in North America also incorporate a disposable filter in the cold air return to cut down on the dust, a feature notable for its absence here. I make my own with felt over a small frame inserted in the return duct.)

All the return air vents I have come across have a light sponge filter in them which most people forget to clean and then they wonder why it gets noisy.
Bob

[Jacksin]

All the return air vents I have come across have a light sponge filter in them which most people forget to clean and then they wonder why it gets noisy.
Bob

True Bob. That was the only problem with my Fujitsu inverter R/C a/c installed in Sept. Fujitsu have changed from the sponge filter over to a carbon very fine-flywire type of filter and the little man in the factory thought it would be a good idea to fit them both.

It sounded like an aeroplane when turned on, something the installers should have heard. Luckily I never used it that month until the serviceman called to remove the sponge once I complained about the noise. He has well over 100 units to fix!

But comparing evap to refrig is no contest, I have lived with both. Its going to be around 37+deg here today and I can drop my inside temp to around 21deg in about 15 mins of medium fan speed. Why would I want a unit that can ONLY drop the outside temp by 10deg? Plus my unit heats too.

[MelbMan]

Hi Jack never having owned a house with evap cooling I was under the impression that evap is cheaper to run than refrig. You see heaps of houses in country area with evaps sitting on the roof. Guess I assumed this was because they work better than refrig.

Our Melb house has about a 30yr old York split system. The a/c still works ok. It's a big house and the ducting runs for miles. It's better than no cooling at all but on a hot day when the outside bricks heat up you might get 10 degrees max below the outside temp.

[Skew ChiDAMN!!]

Evap's are much cheaper to run but, as Jack said, won't drop the temp anywhere near as much as a 'frig unit. Worse, evap's are also of limited use on muggy days... they can make it even muggier or cause condensation on the walls if not operated correctly.

However, I prefer evap's for a couple of reasons:

- I'm always popping in/out of the house and on a real stinker of a day walking out into temp's that are more than 10° hotter than inside the house really drains me by the end of the day. (Perhaps if I was a lounge-lizard who only stuck my head out the door to see whether the sun had set or not it'd be a different story...)

- When SWMBO fills the house with smoke (don't ask ) it only takes a minute to flush the whole house.

[MelbMan]

Trying to work out what you'd classify as muggy when expressed as relative humidity..

For example in the following link relative humidity is expressed as RH

http://www.bom.gov.au/climate/dwo/20...0.200612.shtml

In Dec 2006 the lowest humidity was 11%, the highest 65%, the mean 45%
In Jan 2007 22% 92% 60%
In Feb 2007 21% 89% 59%
In Mar 2007 31% 98% 66%
In Apr 2007 30% 98% 64%
In May 2007 66& 97% 85%

Thanks guys. I can't conceptualize what these figures translate to feeling wise

[woodbe]

Hi.

On a warm day (mid 30's) a relative humidity of around 40% feels moist. Above that people start feeling uncomfortable. Above 60% feels uncomfortably wet. From your chart, there looks to be only the 22nd with high humidity (62%), but the temperature is mid twenties.

There is an interesting page on evap coolers on the breezair site:
http://www.breezaircooler.com/c_more_evap.html

woodbe.

[MelbMan]

Woodbe thanks for your reply and putting it partly into context. It always harder to conceptualize something rather than experience it

[woodbe]

Another thing I've been thinking about since we had an evap cooler is that the water quality does matter. In Adelaide with our cooler running, there was an unmistakable Adelaide water smell in the house when you came inside. Knowing what I know now, i'd have a little filtration and carbon canister filter on the cooler if your water is anything but pure.

woodbe.