An evaporator is a cold and humid environment, so in some situations it can be contaminated with micro-organisms. Cold-loving bacteria such as Listeria survive well in this cold and moist environment.

In time, a biofilm of bacteria will form in the drip tray and on the fins of the evaporator. When there is a high concentration of moulds and yeasts in the air, we also see that evaporators become mouldy.

The risks when you give evaporators too little attention:

Bacteria, fungi and yeasts spread from the evaporator through the air. With fungi this is certainly the case via spores. In bacteria it happens via small drops of water (Aerosols).
That bacteria, fungi and yeasts spread through a drop of condensation water. If a leak or blockage occurs in the drip tray, the organisms will spread throughout the rest of the room.
After cleaning the evaporator (usually performed with a high-pressure cleaner) the organisms are spread throughout the room.

Practical problems that arise:

Reduced cooling function: the micro-organisms form a layer and insulate the cooling fins.
Clogging of the drain: by the aforementioned layer of micro-organisms.
Visible mould on the ceiling in front of the evaporator outlet.

Companies that use evaporators in sensitive areas, usually the food industry, often choose to clean evaporators regularly if the contamination becomes visible or measurable. In this article we discuss the option of equipping evaporators with UVC lamps in order to prevent the growth and spread of micro-organisms. Preventing problems in this case is better than fixing it after they arise.

Disinfection with UVC light

UVC light is able to destroy micro-organisms, that process is explained here. The application of this in an evaporator is theoretically simple and in practice often more complicated.

The main technical requirements:

The fixture and lamp(s) must be water resistant (IP68 or higher) and suitable for low temperatures. Most UVC lamps are not and only work well at room temperature.
To achieve a good result, meaning no visible mould growth and absent or minimal bacterial growth on the slats and in the drip tray, the entire cooling block must be radiated.

The fins of an evaporator are usually made of aluminium and that is beneficial. reflects UVC radiation very well. Therefore, when properly placed, the disinfecting effect is effective throughout the evaporator.

Practical example:

UVC lamps are often placed in the endplate of the evaporator so that they are perpendicular to the fins. Evaporators come in all shapes and sizes, it is important to select the right UVC lamp that fits well with the length of the evaporator. Long lamps should be supported to prevent breakage.

It is important to think about placing and removing the lamps. After the lifetime of the lamp, it must be replaced and it is convenient if the entire evaporator does not have to be disassembled. Most UVC lamps suitable for evaporator installation have a lifetime of 12,000 burning hours.

Safety

An evaporator with built-in UVC light entails risks. UVC light is dangerous for skin and eyes, you can read more about this here. We distinguish three groups of people who are at risk:

Operators
Cleaning employees
Mechanics

For operators:

They are on the work floor for a longer period of time and it is important to be sure that if stray light is present, it is not harmful. This can be done by:

UVC lamps can be built in well (shielded)
Only equip evaporators that hang high enough (safe installation below 3 meters is normally not feasible)
If necessary, only switch on the UVC lamps in the absence of people
In case of doubt, the remaining straylight is measured and it is determined if the work environment is safe in accordance with the European optical radiation guideline.

For cleaning staff:

Can it be ensured that the lamps switch off during work (e.g. together with the fan)
Or can people be trained in manually switching off the UVC lamps before carrying out work.

For mechanics:

Is applying sufficient warning (stickers) and additional training necessary.

Required budget

The costs for installing UVC lamps consist of fixtures, lamps, support in stainless steel 304 and installation.

Example calculation:
For an average evaporator of 160 cm wide, 50 cm high, single-sided discharge and sufficient space for the installation of UVC lamps:

2 fixtures type UVpro FMD-40
4 UVC lamps type 6040DT (Food safe)
4 support brackets in stainless steel 304
Installation in one day, Utrecht region
- Budget price: € 2,564,00
- Exclusive: VAT, installation of electrical supply with isolating switch

Finally:

UVC lamps are food safe (HACCP) available
Bioclimatic provides installation and maintenance in the Netherlands and Belgium
A logical consequence of a hygienic evaporator is a lower germ pressure in the room. This reduces the chance of a product recall and ensures better quality for your customers.
Your investment is quickly earned back through less cleaning work and a higher cooling efficiency.

Prevent that recall, improve your company hygiene and save on your cleaning costs. Contact us for an appointment.