To help maintain high levels of relative humidity within crop storage buildings, Farm Electronics
has developed a unique wall mounting evaporative humidifier which halts damaging weight and
quality loss in potatoes and other food products during storage.
Farm Electronics have utilised the HUMIDRAFT humidifier coil and installed it in a wall mounting
unit. Locating the assembly on a wall gives a compact low profile assembly.
The standard unit with an airflow of up to some 0.85m3/sec it is
capable of maintaining the relative humidity levels at between
95%-98% in store. This enables the replacement of moisture
levels normally lost during cooling operations in storage, yet
required to keep the stored crop in prime condition.
Controls for the humidifier unit are located in a waterproof
remote control. The control panel is fitted with a door interlock
isolator switch, for complete electrical safety and a selector
switch providing Automatic, Off and Manual Run selections. In
the Auto Mode the unit operates intermittently with preset run
and off periods. A simple timeclock controls the operation and
can be set for almost any variation of On and Off periods. A
manual speed control allows the fan air flow to be adjusted as
Base Unit 85cm (w) x 57cm (d) x 120cm (h)
Weight Dry 70 kg Wet 90kg
Fan 500mm dia. 0.85m3/sec 0.8kw 1-phase 1.1amps
Control Panel Epoxy coated enclosure with door interlock
isolator Auto/Off/Manual selector switch and
24hr On-Off Timeclock. Manual speed control
EVAPORATIVE HUMIDIFIER UNIT
Operation and Installation Instructions
Description of the Humidifier Operation
The Humidifier works by constantly dribbling water over two specially treated absorbent paper
elements. The elements when fully "Wetted" provides a large evaporative surface area over which
the air passing over the element can take up the moisture. By constantly passing air over the
elements it is ensured that the air is at the maximum saturation at all times. As the air only takes
up whatever water it can, there is no danger of excess moisture being in the building. Any
water not taken up by the air recycles safely within the humidifier housing water storage tank.
The Farm Electronics Humidifier operates virtually maintenance free and requires no operator
settings apart from setting the Auto On & Off times. After extended operating periods the paper
element may have to be renewed. This will be as a result of water contamination deposits.
Under normal conditions the element life should be a minimum of 2 to 3 seasons dependant on
The remote control panel is very simple in operation. The main switch has an AUTO / OFF/
MANUAL position. In MANUAL the Humidifier pump and recirculation fan run continuously.
In AUTO the unit will run in times "Set On" on the timeclock on the panel. Push the small pegs
in to set "On Times", pull pegs out to set "Off Times". For maintenance the Main On / Off
isolator at the bottom of the box can be used to gain access to the circuit breakers and fuses. The
simple Fan Speed Control allows pre-set adjustment of the fan air flow.
Optional Auto RH Control
It is possible to control the Humidifier on RH level demand if a separate RH controller is
fitted. (i.e. Farm Electronics Model CH1 or CH2)
In this case whenever the panel is switched to AUTO and RH falls below the set point the
Humidifier is started up until the RH rises back above the set level. The inbuilt Timeclock
is overridden. However the Timeclock can still be set and used independently as before if
EVAPORATIVE HUMIDIFIER UNIT
The unit should be securely screwed/bolted in the desired location. The unit must be levelled
using a spirit level. NB. It is very important that the unit is installed level. This is because
the dribble bar must be level to obtain an even water flow over the element. Connect the terminal
box to the appropriate terminals in the main control box. Connect a suitable mains water supply
to the ballcock in the water reservoir tank. It is recommended that a water isolation valve is
fitted to allow future service isolation. Run the reservoir overflow pipe through to a point where
water can be safely discharged making sure that this has a fall to outside along its length. Connect
a 240v ac single phase supply to the main switch of the control panel. The total load of the panel
is 2.5amps. To set up the water flow rate, switch the unit to manual. Adjust the flow valve
behind the service panel at the front, to regulate the water flow from the dribble bar to a steady
trickle over the whole length of the bar. This flow can be viewed through the two small perspex
windows at the top of the evaporative element assemblies. Once these steps are complete the
unit should be fully operational.