Humidification of a Salad Chill

[Pipelini]

Hi,
I could do with some help with regards the design of a raw salad chill. I need to keep the RH up as high as phsically possible and would like to know the best way of going about this? Can anyone give me some pointers?

[NoNickName]

Ultrasound humidifiers, but will also spread bacteria (cold steam).
The cleanest and most hygienic way to humidify is through electrode steam humidifiers or immersed boiler humidifier (warm steam).
Otherwise design a chilled water system with highest possible water temperature, compatibly with room temperature.

[winfred.dela]

Hi,
What's the room/enclosure size?
Just a year ago a friend requested a ref, humidifier unit and room 3M x 3M x 2.8MH with 0oC to 10oC @ 95% RH to 100% RH.
I look for an aircon condensing unit with correct duty compressor, evaporator with around 5 fins per inch for the refrigeration system. For humidifier: look for a small water pump, put in appropriate water nozzle, solenoid valves, some controls, humidity controller, etc.
I installed the room, humidifier, ref system and controls and until now the room operates @ around +5oC/95%RH with not much problem.
If you think this system will be OK for your requirement, will be glad to provide additional details.

[Pipelini]

I am looking for something on a much larger scale; 24m x 18m x 6m high with around 96000kg of bulk lettuce. All stored at +3 degC and 98-100RH.

[NoNickName]

What is the specific heat of lettuce?

[winfred.dela]

I have done a size around 15M x 10 x 5MH for +10C/95RH room and here's what i did:
(1) Compute the cooling load.
(2) Advise the customer to make a room that is almost vapor tight.
Insulated panels with metal skin is best with gasketed doors.
(3) Find an evaporator with coil 5fins/inch.
Better use a software to find the correct fin spacing for your evaporator duty.
(4) Find an aircon condensing unit with the correct compressor duty to suit the evap temp and capacity.
(5) Install water and air pipes using the appropriate air/water spray nozzles inside the room.
I got nozzles from spraying system company. This will deliver very fine water mist.
With your room size you may use around 10 nozzles.
Might be less if the customer will not always open the door.
In another project I installed only one nozzle for room 3M x 3M x 2.5MH @ +1C/95%RH.
The customer supplied the pressurized water tank @ 60psi and air compressor @ 40psi.
(6) Add controls: thermostat for aircon condensing/evaporator unit & humidity controller for the solenoids of the water & air lines.

When the system runs you will feel that you are inside a tropical forest with zero visibility.