Thread: evaporative cooling ?

Evaporative cooling doesn't work very well in humid weather.

I'd stay away from it... As Grunt says, its not going to work very well at all in the humid QLD weather come summertime.

Depending on where he is it may work quite well. Out around the drier areas like Mt Isa or Emerald an evaporative system will work very well. I would think that installing the unit and ducting wouldn't be beyond you as you're well into fairly major renovations. The main part of the unit may have to be lifted onto the roof (crane?) and a section of roof removed to allow fitting. Then you'll need to get some plumbing and electrical work done also. Before purchasing you'll need to look at the existing system to see if there will be adequate ductwork to service your house. If not it will pay to find a source and pricing before commiting to purchase.

Mick

Something you may want to look at first is the price of the ducting. I recently installed a rangehood which vented some 15m away under the eaves using similar ducting materials. The prices for the ducting were horrendus and may have cost in the vicinity of $400. Fortunately the local appliance shop has ducting in 3m lengths that were considably less but still paid $150 for sufficient number to be duct taped together.

well lets see, i think i have installed around 1500 evap units so i think i might know a little bit about it.

Anybody with with a few skills can do it
While i do not know the brand that you mentioned they all work on the same principle. that is evaporating water in the unit and then pushing this cooled air through the house, I assume its a house, the house must have open windows or doors to let the air flow through, but not two many, the idea is to slightly pressurise the house so the hot air out side does not get into the house just the cooled air flowing through it.

First find out what size dropper you have on this unit( dropper is the metal air flow transition that the unit sits on and the ducting is connected to in the ceiling cavity) the standard size dropper is 550x550mm flash with lead for a tiled roof 15kg per M2 is what the standards say, or flash with metal flashing if a tin roof.

duct is connected with duct tape to the y's and to the collars that are fitted to the dropper, these collars can be fitted in several ways, if you have a castelated collar ( they hold themselves in place by bending the metal tabs into place.)

vents are placed in an evap unit the longest distance from the exit point in a room( but take into account how it will look) in bedrooms place the vent above the doors or as near as you can ( roof timbers will determine this, while on the subject of timbers do not cut any roof timbers other than tile battens for a tile roof.) the air will flow around the room & out the window or around the room & out the door longest way will give the maximine amount of cooling, if it goes out the bedroom door this cooled air can then flow through the house to another exit point and give what we call concetrated cooling in that room

i could go on and on so if you want more info maybe you could ask specific Q's and i will answer them for you.

Mick is correct in that evaps dont work well in a humid areas but work best in hot dry areas.

Hope that is of some help
Cheers Ian

just an extra thought

the basic priciple for evap cooling is 30 air changes an hour
that means that all the air in the living areas (dont bother about wet areas) will be changed every two minutes.
make sure that the unit can deliver enough cubic meters of air to do this , if it cant then dont waste your time & money.

plus a drum fan is always better than an axial fan

Cheers Ian