Knowledge/Install and commissioning/Commissioning the water side of an evaporative cooler
Commissioning the water side of an evaporative cooler
Set it up with supply pressure between 100 and 800 kPa and the water level 5 mm above the float valve base. The pump runs for 90 seconds to wet the pads before the fan starts. Flush new pads for 5 minutes on the lowest speed in cool mode, then drain the tank. Repeat several times if needed.
- Supply pressure
- 100 to 800 kPa15 to 115 psi
- Water level
- 5 mmabove the float valve base
- Prewet
- 90 secondsbefore the fan starts
- Pad flush
- 5 minuteslowest speed, then drain
What order do you commission it in?
- Check the supply pressureMinimum 100 kPa, maximum 800 kPa. Low pressure is a common cause of slow fill, and slow fill is what throws the water fault codes.
- Set the water levelOn Breezair coolers, set the water level 5 mm above the float valve base. Clockwise lowers it, anticlockwise raises it.
- Let it prewetIn cool mode the pump runs for 90 seconds before the fan switches on. That's how it's designed, not a fault, so tell the customer and they won't ring you about it.
- Flush the new padsIt's a requirement, not a nicety. Run it in cool mode on the lowest speed for 5 minutes, then drain the tank. Repeat several times if necessary.
- Check it overAll pads evenly soaked, no visible leaks. New pads smell at first, and that's normal. Run the controller's pad flush function rather than booking a callback.
Which plumbing traps cost you a return visit?
Both
get
missed
The solenoid is directional, and the isolation valve type matters
First one, straight from the manual. "Directional arrow must be pointing towards the float valve assembly. If not, water will not shut off." Fit the inlet solenoid backwards and you get a cooler that fills and keeps filling.
The second one is easier to miss. The manual says "Pressure build up in pipes can lock up the solenoid valve when a non-return isolation valve is used." So fit a ball valve as the isolator, not a non-return type of shut off valve.
That second fault shows up as intermittent no water on a system that was perfect at handover, which is about the most annoying callout there is.
What are the electrical and drainage rules?
- The electronics box has a 12 amp resettable circuit breaker
- Controller cable maximum 25 metres to the first cooler
- Up to 40 metres with a link module
- Drain water must not discharge onto the roof surface
- Where pipes can freeze, a drain-down facility should be provided during the installation
That last one is high country, not metro. If you work Ballarat, Bendigo or anywhere up towards the alps, it's a real consideration. In Melbourne it rarely comes up.
What should go in the quote for roof access?
Seeley lists the conditions that attract a roof access surcharge. They're a good template for your own quoting policy.
- Roof pitch over 30 degrees
- Limited roof access
- An access point more than 4 metres above ground
- The cooler too close to a fall edge
- A roof that isn't strong enough to hold the cooler and the technicians working on it
Leave 1.0 metre clear on the front and sides. On XTR and EXQ or EXS units, the rear (slope tank) side needs 0.6 metres. Check that before you commit to a spot on the roof, not after.
Chasing a figure the manual doesn't give you?
Some of them genuinely aren't published, and some of them are published somewhere nobody thinks to look. Either way you shouldn't be guessing.
Tell Kevin what you're after and he'll point you at it or tell you it isn't there.
Who this is for: small and medium HVAC contractors in Victoria. If you're a homeowner after a rebate or a repair, you need a licensed contractor, not us, and yours can point you the right way.
Related
- Add-on cooling needs a second thermistor, and here's whyA cold coil in the supply duct soaks up the heat rise the heater looks for to confirm it has lit. That's why V1.10 boards onwards want two thermistors.
- The outlet thermistor goes 3 metres down the supply ductAbout 3 metres down the supply air duct, never in the return, and never in a zone that closes. Get it wrong and the heater shuts down after 90 seconds.
- Duct sizing, bends and return air on gas ducted heatingAirflow per outlet, when to upsize the duct, minimum bend radii, and the grille table that shows exactly what a filter costs you in return air size.
- Relief air, and the two tests that prove you have enoughTwice the vent area per room, and two field tests you can run with no instruments at all. Plus the published ratio that doesn't exist, whatever you've heard.
Review date: 1 April 2027. Figures in this area change without much notice and this page carries some that will go stale. Every number above is dated and sourced so you can check it yourself. If you find something out of date here, tell us and we will fix it.