Buying a mist unit

[John85]

I'd like to install a small mist system in the greenhouse.Till now i have only used big professional units at work powered by a very high pressure pump or by compressed air.
I was told that the droplets of the small units are often too big and therefore bring too much water and"wash out" the cuttings.
There are plenty of systems to choose from with different techniques.(high pressure,low pressure, turning nozzles,fans,mix air-water......)
What system are you using?How do you rate it?What are its advantages and disadvantages?
Thank you for your comments.

[Maggi Young]

John, I'll get Ian to comment for you on the small mist unit we have here... it 's nothing fancy and did not cost a lot but it works well .... but I know nothing about it!

[John85]

"Did not cost a lot but it works well"
Maggi those words sound like music to my ears!

[Ian Y]

Hi John the unit I have used for years is from Simply Controls and you find a selection of systems at their web site. I have found them very good to deal with with good customer care and support.

http://www.simplycontrol.com/catalogue/mistprop/default.asp

I am happy to answer any further questions.
Ian

[Maggi Young]

Following the link now I see that the price has gone up quite a lot since we got ours!

[Pascal B]

I got my misting system for my glasshouse here: http://www.vivaria.nl/vivaria/?get=menu&menu=climatecontrol&template=menu_climatecontrol.xsl

I bought it to cool the glasshouse down but for a 6 x 3 m glasshouse I need more nozzles than the 10 I got so I am thinking of moving up to a more powerful pump. For my purpose I probably also need a finer mist because I need to take away the heat from the air by evaporation and some of the mist still reaches the floor. The mist is definitely fine enough for a propagation unit with the basic system but you probably need to use one of those leaf sensors to turn it on/off because the pump is slightly on the noisy side and can't run continuously. However, the bigger ones they offer can and also produce more pressure (and therefore finer mist). Prices seem to be comparable with the ones from simplycontrol.com

[johnw]

Ian - re: your mist system.  I see it uses the leaf as the on/off control.  I am not keen on that system as it must be very carefully placed as any wind can  jostle the leaf and cause the mist to come on.  If ventilation is superb then the problem is much worse. Have you experienced this?

A solution a friend recommended was the Aquamonitor. It's a very simple system that can be easily replicated if you can do simple electrical work.  I bought one years ago but haven't used it though others have with success.  The electrodes (?) require a simple rub once a year with steel wool.  It was designed by a clever electrical engineer in the eastern USA (Long Island maybe) and sold from his house.  A good water filtre & pressure regulator is essential to avoid nozzle drip when the solenoid valve disengages. Many mist nozzles now are touted as drip-less and they are if the water source is not too far away.

johnw - raining, howling and +5c at 22:27

[John85]

Ian,Does your system work with only the water pressure delivered by the tap?No extra pump?
Do you think it is worth the extra investment?
Johnw,Is it possible to have a bit more info about the Aquamonitor?May be a picture?

[Maggi Young]

John W.... yes, the head of the sensor need the odd clean to keep it in good order... nothing major.


John85...... yes, only the tap pressure... if your tap pressure is quite good and the distance from the tap to the unit is not too far then I wouldn't think a pump was needed.  I suppose our tap is around four to five mteres from the unit, so quite close and our  local water pressure is good.

[johnw]

Johnw,Is it possible to have a bit more info about the Aquamonitor?May be a picture?

John85 - I will take a picture of the Aquamonitor after the weekend's yard sale - the basement is very chaotic at the moment.

Imagine a straight 20cm length of PVC drain or water pipe (not the perfectly rigid kind) of 7.5cm diameter. The pipe is cut with a rotary saw so there is a .8cm gap running the length of the pipe on one side - i.e. the pipe is somewhat c-shaped.  On either side of the gap two 21cm rods about .25cm in diameter (of whatever metal is best to be electrified) are glued (edit) just below the cut edges of the pipe - i.e. facing one another with a bit of each rod hanging over one outer end of the pipe with a slight gap between them. Now insert a bolt in the piping perpendicular to the cut and the rods at the widest part of the pipe, on the end place a wing nut.   With the wing nut you can vary the gap between the rods as it flexes the pipe. Hook up electricity to the over-hanging rod bits - see caveat below. Set the pipe on your prop bed completely level and in a strategic spot. Hook up to Powe Supply, your solenoid valve and mist system - (edit) see photos posted later. Under mist the gap will fill with water by water tension if the rods are just close enough and shut off the mist.  As the gap water evaporates the circuit is broken turning on the mist.  It will take a bit of time to adjust the gap to get the mist to come on at exactly the right time.  The pipe and rod lengths can be larger or smaller, say 15cm long and pipe 5cm in diameter but you get the idea I hope.

Clean the edges of the rods if any mineral/salt build up occurs.

I take no responsibility for any electrocutions, consult an expert before plugging in. A ground fault interrupter is essential.  I have personally witnessed the fury of UK electricity gone wild and it is far worse than anything here.

johnw

[John85]

Johnw What voltage do you use for your system?12V  24V or more ?AC or DC

[johnw]

John  - I will have to find the Aquamonitor before I can answer that. 

johnw

[johnw]

John85 - Here are the pix of the various components of the Aquamonitor. I bought a tower (yellow cap screws onto the male end of the valve and the black lines are water lines) and a mist line for a bench. I will scan the instruction sheets. Obviously I missed mentioning the Solid State Power Supply which is rather critical!

I will scan the instruction sheets tonight and post. Seems anyone could build the sensor which works a treat and note the electrodes are not quite glued to the edges of the recess.

A friend used this in his prop house for a 7 metre x 2 metre bench. It lasted for 25 years until the PVC pipe snapped along the bottom edge, he built one himself as a replacement.

johnw

[John85]

Thank you Johnw,
One picture is worth a thousand words!

[johnw]

Thank you Johnw, One picture is worth a thousand words!

If anyone wants the set-up instructions please send me your email address. The scans would not be readable on the forum conforming to the pic size limits. It may take me a few days to get them done.

johnw