Evap Cooling. Please Help!

[woodbe]

We've had both evap systems and reverse cycle, and there are pros and cons of each.

Evap works better the dryer the climate. If you look up the wet bulb depression for typical summer days in your area, you will get an idea of the best that can be expected temperature wise. From memory, in Adelaide's summer, we are looking at around 7 degrees, so a 30 degree day will have 23 degrees air coming out the outlet, 40 degrees will have 33 etc.

If you want your house to be like a fridge, evap won't suit you on the hotter days. On cooler days like mid-twenties, it will probably get too cold!

When sizing the system, the installer should plan based on a formula of the volume of the air in the house and how fast that air changes to achieve a comfortable environment. The more humidity, the greater the number of changes required to make it comfortable. Which is why there is not much evap cooling in Townsville, because you cannot stand up in a tornado

Anyway, we put evap cooling in an old stone home we had with 3m ceilings and it worked brilliantly. We sold it, but it's still in use and it's been there for about 15 years. evap is also pretty good for eliminating smells and odors from the house. It just blows them next door If you run a duct to the workshop, it could be good for blowing the dust away before it gets to your lungs too.

woodbe.

[oohsam]

Oh, Im not saying we cant have evap coz of teh 3m cielings, just need a more powerfull unit.

Just goin off topic a little..did you know this was your 666 post...hmm....el diablo...talking about the heat and what not..im a little sus..

seriously though, My parents have evap, and it does a really good job, make syou much more comfortable in the home. I know it wont be ideal but it will cool me down.

[woodbe]

Ok, got to get off 666 fast...

There is a lot right with evap, it's just that some people have a fixed idea of what air conditioning means, and evap is not it. On the other hand, evap moistens the air, is far more environmentally friendly, and doesn't require you to shut all the windows and worry about the cool air escaping. (like your fridge)

It's basically a very good, simple and economical idea.

woodbe.

[oohsam]

Thats why they call Evap "cooling" and refreigated is "air conditioning"

[SilentButDeadly]

We've an ancient Bonaire on our place that has become something like Grandad's axe...

With regard to the various brands - http://www.climatetechnologies.com.au/ own Bonaire and Celair while Breezair, Coolair and Braemar are all from the same company, www.seely.com.au
....they just have different levels of sophistication.

The main thing to remember with evap.....they need to be able to move air through you house so they either have a roof vent or you need to leave a window/door open AND they typically can lower the ambient temperature by AT MOST ten degrees...so on a low 40's day you are still experiencing low to mid 30's in the house.

Oh and our mulberry and plum trees get the drainage water. One day it'll go into our greywater system.

[rrich]

When I lived in Phoenix, Arizona we had a swamp (evap) cooler for about 18 months. When the humidity was below 15% it worked so well that we would turn it on and off because the house was getting too cool.

When the humidity was 15% to 25% the cooling was not so good but mostly comfortable.

When the humidity was 25% or above it was better to endure the heat and open the windows.

Based upon your quote of $4500, it seems that a refrigeration unit might be a better investment. I recently had a furnace and old refrigeration unit replaced and the cost was only $4800. The evaperation (cooling) coil was installed on the top of the new forced air furnace. (Similar configuration to the old.) If you already have forced air heating, the duct work to install refrigeration is almost nil.

[oohsam]

I dont know what forced air is, but are you saying you can put a refrigiated unit in place of teh evap unit?

[Greg Q]

Forced Air=ducted.

In North America it is common to use the heating ducts to carry cooled air from the central air conditioner. Ducts are installed in the floors, not the ceilings, but this doesn't seem to be an issue.

(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.)

I too think evaporative is a waste of time, and possibly subject to future restrictions (if the water situation worsens?). Melbourne summers seem to be getting more humid...our evaporative does ok only some days...the others are made even more horrible for the added humidity and little if any cooling.

[coastie]

I second the argument about evaps being useless when temp is hovering
around 30-40 mark.House sat my daughters house in Perth last January,Australia Day was 46degrees! Just couldn't cool down, evap was working flat out,just wasn't making any progress.Eventually went down to the river that night to watch fireworks and cool down with a coldie!What a day! Never ben so hot in my life!

[coastie]

I second the argument about evaps being useless when temp.is hovering
around 30-40 mark.House sat my daughters house in Perth last January whilst she was in NZ,Australia Day was 46degrees! Just couldn't cool down, evap was working flat out,just wasn't making any progress.Eventually went down to the river that night to watch fireworks and cool down with a coldie!What a day! Never been so hot in my life!

[rrich]

I too think evaporative is a waste of time, and possibly subject to future restrictions (if the water situation worsens?).

The evap coolers that I used in Phoenix had a 150mm deep tray to catch the un-evaporated water from the pads, a small electric pump and a toilet cistern fill valve. Wheh the evap cooler was running, the pump would move the water to the top of the pads and the cistern fill valve would add water to the tray as needed. The water source was the city supply. Water usage with this system was insignificant.

The heating system (Forced Air) was typically natural gas fired. A blower would move the air through a filter, (disposable fiberglass) up through the furnace heat exchanger and then into the ducts for distribution through the house. There is usually room on the top of the furnace for the A/C cooling coils so that the system could be used as either a heater or an A/C system.

[woodbe]

The evap coolers that I used in Phoenix had a 150mm deep tray to catch the un-evaporated water from the pads, a small electric pump and a toilet cistern fill valve. Wheh the evap cooler was running, the pump would move the water to the top of the pads and the cistern fill valve would add water to the tray as needed. The water source was the city supply. Water usage with this system was insignificant.

Yes, that's pretty standard, and it's the way they work over here mostly too. There should be an adjustable bleed to waste on the system as well, because you are evaporating water and concentrating the salts etc in the water supply - if you don't do this, you land up with something approaching brine in the tank.. It's adjustable because some areas have higher concentrations of dissolved salts than others. Over here in Adelaide, we probably have to bleed off as much or more water than we evaporate...

woodbe.

[wood duck 2]

Apparently there is some new evaporative cooler technology available in the USA.There is no agent here in Oz but it might be worth checking out this website.www.coolerado.com
cheers.

[MelbMan]

I'm interested in putting a new Bonaire in a house up in the Mallee....about 200km south of Mildura. Very hot up there in summer. Wonder how evap will go? The house has one refrig a/c unit in one of the windows in the lounge.

Shop around for evaps. I was quoted nearly $3500 for a unit plus installation. Have found I can buy the unit for nearly half that.

[Skew ChiDAMN!!]

Don't forget that where a split unit can be installed in under an hour, a swampy will take a pair of blokes all day to install and the larger unit's dropper boxes can mean a rafter may need to be cut out, which means the addition of underpurlins & struts or purlin props. Truss rooves can be even worse... it used to me off to the max when the client said "but the salesman looked in the ceiling cavity and said it'd fit no problems!" Yeah, sure... no problems for him - it was the installer's headache.

(Sorry. I think someone slipped a soap-box under me while I wasn't looking. )

Also, when you buy a swampy seperately, very rarely does the price include the ductwork and fixtures, flashing, wiring or plumbing.

I'm not saying that this justifies some $1500+ price difference but it does account for a pretty big chunk of it.