controlling humidity in display inclosed cases

[mattmechanic]

Hi all,
i have a customer who has some custom made display cases ( approx 10 years old )
they are fan forced and he has had to cover the product with gladwrap to prevent it drying out.

now with competition and so forth he wants to display his product without having to cover it ( mixed goods, cakes, sandwiches ect

do any of you know of a humidifying product you can put in a case to control humidity?

as i am dreading the idear of turning them into a cold plate with cross fin type setup..

i have done all the ushuall lower fan speed and ajust TD, sponges in water ect and still no luck

any more ideas would be appreciated

[chemi-cool]

Usually, the manufacturer should state the purpose of the case.
If you are working with evaporation temp below 0, the unit will collect more water from the air.
To keep the case humidity high it needs to have a large fin spacing and high {as possible} evaporation temp.

Adding humidifier might help bacteria grow faster.

Cakes and sandwiches should be wrapped anyway but the best method of cooling them is a cold plate situated above the products.

[B G Scott]

There are purpose made ultrasonic humidifiers (no heat added to the system).
The distribution tubes can be fitted within the coil space and the cabinet fans circulate the humidified air over the product.
We have had very good results with fresh meat cases.
The humidifier can be located external to the cabinet and fed from a storage vessel, it is recommend that the water is treated to prevent the build up of lime scale on the generator plate.

[mattmechanic]

scott, where would i be able to acquire one of those units? do they come with there own controll?
thanks!

[B G Scott]

I don't know where you might obtain them in your part of the world, try a Google search first if that does not produce results PM me and I will send you some links.
The units we have used were self contained and automatic in operation.
For the distribution tubes we have used 22mm plastic with holes drilled along its length and located it with the fan plenum chamber.

[Magoo]

Increase SST in evaporator with a EPR, will reduce latent cooling and increase sensible cooling and increase humidity in case.